I think the real power here is enabling AI to use all the stuff we've built already. Don't need to rebuild everything for AI. I've been through enough replatforms to know that we can't rebuild everything from scratch.
I think we do need to build new interfaces, though. The existing ones were designed for humans to use, either GUIs for end-users, or APIs for developers. But LLMs have very different reasoning patterns. They even make mistakes in different ways.
What I've experienced in practice connecting LLMs to existing APIs is that LLMs fail miserably with the interfaces, but simply "translating" the interface in a way that is easier for them to "understand" solves the issue.