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.
Could you provide the code you use to trivially catch signed overflows? My impression is the opposite: unsigned is trivial (just test `a+b < b`) while signed is annoying (especially because evaluating a potentially-overflowing expression would cause the UB I'm trying to avoid).
Avoiding UB for performing the signed addition/subtraction/multiplication is trivial - just cast to unsigned, do the operation, cast back. In standard C23 or GNU C11, you can write a `make_unsigned` and `make_signed` macro using `typeof` and `_Generic`.