Also, I don’t think there is anything in the C, respectively C++ standards that forbids, respectively requires name mangling. Linking isn’t specified in either standard.

C++ implementations have name mangling because they live on systems designed for C, which don’t allow symbols such as int max(int,int)

C implementations (would) need name mangling if they ran on a system that used case-insensitive comparisons on symbol names, or on ones whose character set is smaller than that allowed in C symbols (I know examples of neither, but Wikipedia has an example that encodes the calling convention in the symbol name: https://en.wikipedia.org/wiki/Name_mangling#C)