The fact that C++ is so widely used reflects the fact that it’s both old and acceptably designed. It does not even remotely indicate that it’s universally a good tool choice.
I think C++ is not a great choice for complex crypto software because it doesn’t have very good safety-by-construction properties and it has to deal with (extremely) untrusted and probably malicious input. Parsers written in C or C++ are historically one of the biggest attack vectors out there.
I think C++ is not a great choice for complex crypto software because it doesn’t have very good safety-by-construction properties and it has to deal with (extremely) untrusted and probably malicious input. Parsers written in C or C++ are historically one of the biggest attack vectors out there.