Every blockchain must balance long-term security with coin scarcity. Cardano and Bitcoin share key features, including Nakamoto consensus, the UTxO model, and a capped supply. Ultimately, their sustainability and security will hinge on a single factor: on-chain activity. The ways to ensure security are different for Cardano and Bitcoin. The Reserve Fund is Gradually Depleting Both Bitcoin and Cardano employ a capped supply, which means new coin issuance will gradually cease and transaction fees must eventually sustain the network incentives. Cardano’s ρ (rho) parameter allocates 0.3% of the reserve fund to staking rewards every epoch, adding this amount to the reward pot alongside transaction fees. Stake pool operators (SPOs) and stakers receive their rewards every 5 days. Bitcoin uses a similar mechanism through halving, though its approach differs. Bitcoin miners earn 3.125 BTC per block, plus all transaction fees included in that block. The miner (or pool) that successfully mines the block receives the reward. Unlike Cardano’s gradual reserve allocation, Bitcoin undergoes a halving event every 4 years, reducing the fixed block reward by half. After the next halving in 2028, the reward will drop to 1.56 BTC plus transaction fees. Currently, both Bitcoin and Cardano rely almost entirely on their reserve funds, with incentives about 99% dependent on these allocations. Transaction fees play a minimal role, contributing only a fraction of the rewards. However, this balance must shift over time. As reserves gradually deplete, the long-term security of both networks will increasingly depend on transaction fees rather than reserve payouts. Ensuring high transaction volume and consistent fee generation will be critical for sustainability. Satoshi Nakamoto envisioned that, as the reserve fund depleted, Bitcoin would become securely sustained by transaction fees. However, this has not materialized. The decline in fee revenue during bull markets highlights the issue. In 2017, Bitcoin collected 100–200 BTC per day in fees. By 2021, this dropped to 50–100 BTC daily, and in 2025, it has fallen further to just 5–10 BTC per day. Instead of fees increasing over time, as originally expected, they have steadily declined. The broader crypto industry is facing a declining interest in on-chain transactions, affecting not just Bitcoin but also Ethereum and other blockchains. Users prefer cheaper and faster transactions on Layer-2 solutions, posing a serious challenge for all Layer-1 networks. Economic Security Requirements The two networks have very different consensus mechanisms, leading to different cost structures and complexity for operators. Bitcoin uses Proof-of-Work (PoW), meaning miners expend computational work (and energy) to compete for each new block. This process is extremely energy-intensive. The Bitcoin network’s annual electricity consumption is on the order of 100–200 terawatt-hours (TWh), roughly comparable to a medium-sized country’s power usage. In contrast, Cardano uses Proof-of-Stake (PoS), where SPOs (block producers) are randomly elected to mint blocks based on the amount of ADA staked, not based on energy expended. This makes Cardano far more energy-efficient and cheaper to operate. The difference is about of five orders of magnitude. For Cardano SPO, the ongoing costs are mainly server maintenance and bandwidth. ADA stakers have virtually no operating costs at all. Miners in Bitcoin, however, incur substantial costs: they continuously draw electricity to run mining rigs and must frequently upgrade hardware to more efficient models. Bitcoin’s consensus security is paid for with high ongoing economic costs, whereas Cardano’s security is maintained with minimal energy expenditure and infrastructure that is far less costly to run. Since the security of protocols is to be paid for primarily through transaction fees in the future, it may be much easier for Cardano to maintain security. Security in Numbers In epoch 561, Cardano distributed 7,668,296 ADA in staking rewards, which is approximately 1 million USD per day. Bitcoin mines a new block every 10 minutes, totaling 144 blocks per day. On average, it collects 5–10 BTC in daily transaction fees. The Bitcoin daily reward is calculated as: Daily reward = BTC price × ((Block reward × 144) + fees) Using 100K USD per BTC, the calculation looks like: Daily reward = 100K × ((3.125 × 144) + 10) = 46M USD per day Bitcoin currently pays miners 46 million USD per day. A significant portion of Bitcoin’s block reward revenue goes straight into covering miners’ expenses. Mining is a competitive industry with slim margins; miners must pay for electricity, facilities, cooling, and hardware purchases. Estimates vary, but many industrial Bitcoin miners spend on the order of 50% or more of their revenue on electricity alone. Over Bitcoin’s history, we’ve seen waves of miners shutting off machines when profitability dips, then resuming when conditions improve. Bitcoin’s mining ecosystem continuously balances on a knife-edge of profitability, closely tied to coin price, energy costs, and halvings. The Cardano network is more stable in this regard. Uncertain Future Now, let’s dive into the technical perspective of blockchain sustainability. Bitcoin can only process 7 (TPS), meaning that to generate 46M USD per day, the average transaction fee would need to be 76 USD. Since Bitcoin relies on market-driven fees, users compete to secure block space. When demand spikes, fees soar so high that many users stop transacting—causing fees to drop again when demand decreases. For long-term viability, it’s more effective for blockchain networks to scale efficiently while maintaining low, predictable fees. Cardano adopts this approach by using fixed, stable transaction fees, making it more attractive to users. If Cardano’s blocks were constantly full, it could collect approximately 200,000 ADA per day, or about 150,000 USD. However, this is still 10 times lower than the amount needed to eliminate reliance on the reserve fund entirely. Unlike Bitcoin, Cardano is a SC platform with a clear plan to increase scalability. Its technological framework is designed to ensure long-term sustainability. Another challenge for the entire industry is to fill the blocks. It is not enough to have the technology, you need to have demand for transactions, i.e. real-world utility. The market value of coins plays a crucial role in blockchain sustainability, especially when on-chain activity is low. Even if only a small portion of reserve funds is used for rewards, a high or rising market price can help keep the network economically viable. Bitcoin currently has the advantage of being a widely recognized investment asset, with growing interest from governments and institutions. This gives Bitcoin an edge over Cardano in terms of global financial integration. If Bitcoin reaches 1M USD per BTC by 2032, it will distribute over 100M USD in daily rewards, exceeding today’s payouts. While Bitcoin's security model looks sustainable in theory, reality may unfold differently. If BTC remains at 100K USD in 2032, security would decrease fivefold. By 2052, the block reward will drop to 0.024 BTC, meaning that even at 1M USD per BTC, only 3.5M USD per day will go toward security from reserve funds. Investors and institutions expect security in major crypto assets to grow or at least remain stable, but Bitcoin cannot guarantee this over decades unless fundamental changes occur. It is difficult to predict whether the store of value narrative can ensure Bitcoin's security. At least there is hope. Cardano cannot rely on the store-of-value narrative alone. Its long-term success depends on network utility and adoption, meaning it must focus on building technologies that drive real demand. Cardano, like all blockchains, will rely more on transaction fees than Bitcoin. If internet services adopt blockchain at scale, transaction fees will reflect this demand. If they don’t, many blockchain economic models could collapse. The future isn’t black and white. Other blockchain coins may become stores of value or gain worth through different incentives. For Cardano, on-chain governance and staking rewards provide strong reasons to hold ADA—advantages Bitcoin lacks. However, predicting how these dynamics will evolve remains uncertain. Despite their differences, Cardano and Bitcoin can complement each other. If Bitcoin’s protocol is to remains unchanged while BTC’s economic importance grows, Bitcoin holders could find valuable utility for their coins on Cardano, benefiting both ecosystems.
