Humans, but mostly by accident tbh. Nobody's going to sit down and decide "ok AI drives the ecosystem now", it'll just happen because the tooling is useful and everyone keeps using it. Ecosystems don't really collapse cleanly anyway COBOL is literally still doing bank transactions in 2025. So probably same thing here, long tail of codebases nobody wants to touch, new stuff increasingly AI-generated. The "who owns it" part is where it gets weird though.