Comment by aidenn0

C also has a (granted very small on Unix) runtime[1]. On windows the C runtime is a bit larger, since windows processes get a single string for their arguments, which must be parsed into argc/argv.

As far as "you have to also dynamically link the C++ runtime", try calling malloc from two different libc implementations in the same process and see "interesting" things happen. Even more interesting is calling free() on a pointer that was malloc'd from a different C library.

1: E.g. for musl https://git.musl-libc.org/cgit/musl/tree/crt