If anything, a lot of the modern developer experience has suffered compared to the early Borland IDEs. One would easily say we regressed.

They were focused, immediate and effective.

If anything today you'd miss the code navigation features (go to definition, go back, go forward), and of course LSP is actually very useful and once you don't have it, it hurts (instant errors, ease of refactoring...)

Give me something like the Borland IDEs (FAST!) and some of the modern features (they can be slower, they're only as fast as the LSP server implementation anyway) and I'm there!

I did a proof of concept quickly, mostly while learning to write code editors, but I have not gotten it to a point of being useful [1]

[1] https://imgur.com/a/BexhJ12

We just have to look at the praise Go gets for its compilation speed, versus coding Turbo Pascal and Turbo Basic in a 10 Mhz PC with 640 KB.