Mine is that the useState hook is an actual plague on the entire React ecosystem. Regardless of your opinions of React, if you wanna use something then use it right.
Zed is totally open source, and the AI "features" are optional. When you set it up - at least when I did - it's one checkbox to disable. I don't remember about the telemetry you will have to have a look, I'm usually ok with that myself.
I came from VSCode and haven't found anything I miss. I especially don't miss the poor performance of VSCode, Zed is extremely lightweight!