I mean, targetting musl means pretty much using a different operating system than GNU/Linux. The ELF linking semantics pretty much enforce that you're using the same libc implementation for your whole program.
That's like complaining that, say, a program built against cygwin on windows, can't work on a system without the cygwin dll (and all its dependencies also compiled against the cygwin dll).
That's like complaining that, say, a program built against cygwin on windows, can't work on a system without the cygwin dll (and all its dependencies also compiled against the cygwin dll).