Great debugging capabilities, time travel debugging, data break points, attach to running processes, remote debugging etc.

I think the most important feature for an IDE is debugging - at least this is the feature which separates an ide from just a Text Editor

Native vector search would be great. I was just thinking today how irritating it is to try to find some specific component in a very large codebase without knowing exactly what it’s called already.

You mean like Zed? Check their roadmap.