I realized I hadn't checked for config related problems. When I renamed kritarc, Krita worked the next time I ran it! So something in that config was bad. I've confirmed on my trixie machine that it has the same effect there -- krita crashes on startup if I use kritarc-broken as my config.
I've attached the broken config, and the working config that was created after re-running Krita. There are a lot of diffs, but maybe this will help someone track the problem down.
kritarc-broken
Description: Binary data
kritarc-working
Description: Binary data
