That sidebar of past chats is where they go to be lost forever. Nobody came up with a UI that has decent search experience. It's like reddit internal search engine, but a bit worse.

Exactly. The best they came up with is a generated subject-like summary. So many options to explore here. Categorization by topic, by date, by customer account, clustering by topic, search with various ranking options, conversation(s) tree view, histogram per date/topic/account, integration with email, with an issue tracker, various states per chat/thread e.g. resolved/ongoing/non-viable, a knowledge bank to quickly save stuff you learned (code snippets, commands, facts), integration with Notion or a wiki etc etc. Just off the top of my head.

I was told there would be rapid prototyping with AI. Haven't seen any of the above.