Even if non standard, all major C++ compiler vendors have provided similar features on their standard library, and is now officially supported in C++26.
I have debugged enough C memory corruption issues with strings and arrays, that I would thought by now WG14 would actually care to fix the root cause, 40 years in.
Also to note that said extension only exists because Apple did the work WG14 did not bothered to do for the last 40 years, and as way to improve interop with safe Swift.
At least WG21 eventually did the correct thing and placed those extensions into the standard, even if due to governmental pressure.
Also while enabling bounds checking has been a common configuration option in all C++ compilers, clang and GCC aren't all C compilers.
This kind of discussion is also quite telling that nothing will change on WG14, maybe eventually who knows, C2y might finally get fat pointers if voted in, and then we will see during the following decades whatever fruits that will bare.
When we will have a standard for bounds checking arrays and pointers remains to be seen, but this does not stop anyone from using the non-standard tools available today.