While I agree with your point overall, it's important to note that libc is definitely not a must on some platforms. On Linux in particular, the Kernel user-space ABI is stable, so you can write your own system calls in whatever language you want.
Also, even if you chose to use some libc for system calls, there is no reason to use malloc()/free(). You only need mmap() or similar, and then your own language runtime can write their own user-space memory manager.
As a side-note, on Windows, libc isn't even a system library. The official way to execute system calls is using win32, and things like malloc()/free() are simply wrappers around HeapAlloc() and HeapFree().
Also, even if you chose to use some libc for system calls, there is no reason to use malloc()/free(). You only need mmap() or similar, and then your own language runtime can write their own user-space memory manager.
As a side-note, on Windows, libc isn't even a system library. The official way to execute system calls is using win32, and things like malloc()/free() are simply wrappers around HeapAlloc() and HeapFree().