Why does every L2 sequencer extract MEV that European regulators now classify as market abuse?

Every major Ethereum L2 as of mid-2026 runs a centralized sequencer that captures MEV from transaction ordering, and regulatory analysis published in Q4 2025 provides the first formal taxonomy placing sandwich attacks and front-running squarely within MiCA market abuse categories. Any L2 operator serving EU users is now under legal obligation to avoid this behavior, but no compliant sequencer architecture exists in production. Decentralized sequencer proposals from Espresso Systems, Astria, and the Superchain roadmap are 12 to 18 months from production readiness. The gap between legal obligation and available infrastructure is current and is widening as MiCA enforcement matures.