The mathematics underlying zero-knowledge proofs has been understood since the 1980s. The computational cost of generating and verifying them was, for most of that period, prohibitive for practical applications at scale. What changed over the past several years was not the theory but the engineering: proof generation times dropped by orders of magnitude, hardware acceleration made ZK computation economically viable, and a generation of cryptographers trained in both theory and systems engineering turned their attention to making the technology work in production.

There are currently more than fifty active Layer 2 networks built on Ethereum. This number will not survive the decade. The economics of blockchain infrastructure are not hospitable to fragmentation at this scale, and the user behavior data — liquidity concentration, developer activity, transaction volume — already shows the consolidation dynamic beginning.

The Layer 2 thesis was always that Ethereum’s base layer would serve as a settlement and data availability layer while the actual computation of user transactions moved to cheaper, faster chains that periodically committed their state back to Ethereum. The rollup architecture — optimistic and zero-knowledge — provided the cryptographic guarantees that made this delegation trustworthy. The thesis was sound. The execution produced an overcrowded market.