It's actually an error I've seen multiple times in the past, and I'm not even working with databases full time. I do think it's surprising that no one had thought of implementing at least checks for these conditions.

Yeah, I think most people who touch/interact with backend/database code, even if not actually backend/DB developers, have a reaction nowadays to seeing auto-incremental IDs because it's famously hard to scale to any distributed architecture + introduces issues when you hit the limit.

Projects started in the last three years that I've collaborated/been part of have all ditched the auto incremental IDs.

Auto incrementing integer ids have some very desirable properties though. Not sure what you replaced them with.

Something I see more and more is a primary key based on guid/uuid;

I'm not fully aware of the merits of either approach, so I'm just putting the info I have at hand out there.