Keychain Access has not been "fine". It's had multiple unaddressed data loss bugs. For example, Keychain lost all passwords from all Keychains after the Catalina update[1] and this wasn't fixed in the next 3 Catalina minor updates. Multiple users reported the issue to Apple and the response was crickets. Even if you restored the passwords, it helpfully deleted them all again. I switched to 1Password and declared Keychain Access a lost cause. I don't think I'll be giving them a second chance here.
Depends on how we define "fine," but your own post clarifies that it was "website passwords -- but not app passwords, secure notes, certs, or keys." That's a pretty big difference compared to "all passwords" and seems like it affected a small number of people. In any case, if we're using anecdotes, I haven't had any issues with it so far and it's been decades. Given how 1Password has been getting shittier over time, I've been looking for an alternative, and I for one am going to give this a shot. You can check in with me in a few more decades and ask me if it went okay.
[1] https://discussions.apple.com/thread/250722178