Aside from the NULL-termination requirements there is arguably another big design issue with libc strings. I believe the interfaces that may allocate memory - must give you an opportunity to override the allocator. Aside from the SIMD implementation quality and throughput on Arm, that was one of the key reasons to start a new library: https://github.com/ashvardanian/StringZilla/blob/91d0a1a02fa...

Also not a huge fan of locale controls and wchar APIs :)