That's crazy. I use it on a small-medium Python project (100-200 files) every day and have never had any performance problems whatsoever. I did use the MyPy language server at first, which would take a few seconds to update type errors because MyPy wasn't designed for IDEs. But the UI thread remained responsive during that time. Eventually I switched to the Pylance language server which doesn't do a perfect job with checks, but gives feedback instantly.

How big is your project, and how big are your files? I've had massive JSON files (100MB or so) cause some slight jank in the UI, but that's about the only example I can think of.