Extended hours volume staying under 1% isn't purely regulatory inertia—it reflects thin liquidity and wider spreads when market makers don't want to commit capital overnight. Bitcoin's 24/7 markets have the same problem (weekend/overnight spreads are notably wider on most exchanges); it just doesn't get flagged as a "failure" because there's no comparison to a primary session. The real difference is settlement: equities still batch-settle T+1, so continuous trading without continuous settlement just creates more reconciliation risk, not more actual liquidity.