I think you have something misconfigured, or are timing incorrectly. I'm working on a project right now with ~10K LOC. I haven't timed it, but it's easily <= 2 seconds. Even if I nuke MyPy's cache, it's at most 5 seconds. This is on an M3 MBP FWIW.
I’ll still be switching to the astral offering as soon as it’s production ready.