Once the UI soup around AI dev use has settled (and it's getting closer) I bet you we will see native apps with c/c++/zig/rust backends that render so much faster on all the junctions that aren't roundtrip limited (and yes, that will still matter to many people).

Why would you bet that? It hadn't happened before AI so not sure why it would now. In fact this is why VSCode was even created, because it was easier hacking on a browser renderer than making something from scratch.

These are two of the fastest editors, and I use both, but I don't think they're for the same thing: Zed is for multi-file projects with moderate IDE abstractions (Worse than Jetbrains; better than most others); Sublime is for editing one-off files with syntax highlighting.

On the contrary, I am glad that the Sublime team did not fall for the trends and avoided adding AI slop into the editor

I would bet in time they are vindicated. Then Google et al will release something with much advertising hype about "returning to basics" or something in a couple of years.