Avalanche founder Emin Gün Sirer has warned that Bitcoin's long-term security risk comes not from quantum computing or rival tokens, but from falling miner rewards. He argues that the incentive model could become a larger concern than previously thought.
Block rewards halve every four years, squeezing miner income
Bitcoin miners secure the network by using computing power to validate blocks, earning block rewards and transaction fees. But each halving cuts the block reward by half, gradually shifting the burden onto fees. According to Crypto.news, CoinShares estimates 15% to 20% of the global Bitcoin mining fleet is unprofitable under current conditions, with older machines and high-cost miners hardest hit. The same report called Q4 2025 the toughest quarter for miners since the April 2024 halving, with hashprice near five-year lows and listed miners' average cash cost to produce one Bitcoin at about $79,995.
Sirer proposes a pre-consensus layer, but community pushback likely
Sirer suggested Bitcoin could adopt a pre-consensus layer to reduce base network load and improve efficiency. That idea may face resistance from a community that prefers minimal changes to the base protocol, especially those affecting security. His claim that shrinking rewards pose a bigger risk than quantum computing depends on future fee levels, miner costs, hardware improvements, and Bitcoin's price. Separately, Binance founder CZ's recent comment was taken out of context: he said Bitcoin could theoretically be replaced by better tech, but still called BTC "global money."