Avalanche founder Emin Gün Sirer has issued a stark warning about Bitcoin's future, arguing that its shrinking mining rewards pose a more immediate existential threat than quantum computing or competing cryptocurrencies. Speaking in a recent interview, Sirer highlighted that the network's security model depends on miners being adequately compensated as block subsidies decline.
Bitcoin's protocol halves mining rewards approximately every four years, with the next halving expected in 2028. Sirer contends that as these rewards diminish, the economic incentive for miners to maintain network security could weaken significantly. This dynamic, he suggests, could leave the network vulnerable to attacks.
While quantum computing has long been cited as a potential long-term risk to Bitcoin's cryptographic foundations, Sirer dismissed it as a distant concern. Instead, he pointed to the immediate economic pressures facing miners as block rewards drop. The network currently relies on a combination of block subsidies and transaction fees to incentivize miners.
If mining becomes unprofitable at scale, hash rate could decline, potentially making the network more susceptible to 51% attacks. Sirer's critique underscores a broader debate within the crypto community about Bitcoin's long-term sustainability after all 21 million coins are mined, expected around 2140.
Critics note that Bitcoin has survived multiple halvings without major security incidents, and transaction fees have historically increased to partially offset declining subsidies. The debate remains speculative until the network faces actual reward exhaustion.