I like to be AI sceptical as well but I think it's even more noticeable if the flaw is in 20 year old code which thousands of people have read and reviewed and not noticed, isn't it?
The recent signed keys being '4' is an example.
Looks good, validates, works, and then trust is assumed.
Hardly anyone reads and reviews in open source. It is a myth from ESR. Probably one person wrote it and another one said LGTM.