C and C++ prioritize performance over correctness (2023)

You can implement C in completely different ways. For example, I like that signed overflow is UB because it is trivial to catch it, while unsigned wraparound - while defined - leads to extremely difficult to find bugs.

Signed overflow being UB does not make it easier to find in any way. Any detection for signed overflow you can write give that it's UB could be found if it were defined. There are plenty of sanitizers for behaviors that are not UB, at least for other languages, so it's not even an ecosystem advantage.

One can have sanitizers also for defined behavior. The issue is that a sanitizer that has no false positives is about 100x more useful than a sanitizer that has false positives. You can treat each case where a sanitizer detects signed overflow as an error, even in production. You can not do this same when the behavior is defined and not an error. (you can make it an error and still define it, but there is not much of a practical difference)

If you think signed overflow is a mistake, you could forbid it from your code base, even if it weren't UB, and then any instance of it that a sanitizer finds would not be a true positive, because your code style forbids signed integer overflow.