Have they fixed the stability issues yet? When I last looked at ESP32-CAM a couple of years ago, it was so unstable as to be unusable. Have newer versions of software and/or hardware made an improvement?

I don't know. Got one myself a short while ago but have not gotten to trying it out yet. I'd be quite surprised if it hasn't improved over that time though.

This is cool, and I have one of these! It's performance can be surprising both ways: somehow I am both underwhelmed and impressed at the same time.

I'm for sure looking for an alternative though.

esp32-cam is just ok. the quality of the camera is generally very very low. it also can't do h264 meaning that certain integrations like streaming/recording/detecting motion in apple home will require you to do transcodes on some other hardware (which can get expensive).