Not really that much In my experience. Most of the unsafety is very obvious and most of the memory safety really come from errors from this obviously unsafe parts, e.g. the most common memory safety bug is pointer arithmetic gone wrong. The others are temporal memory safety and signed integer overflows. None of this is really subtle or what I would really call a footgun. Nowadays, programmers do not seem to understand integer conversion rules of C anymore (although they are simply IMHO), but then this is something which can be mitigated via sanitizers.