Oh there were lots of other compilers. Hardly anyone used them because they didn't work with any existing tooling and IIRC most of them didn't even let you to l

Oh there were lots of other compilers. Hardly anyone used them because they didn't work with any existing tooling and IIRC most of them didn't even let you to link the system's UI libraries due to ABI issues and unsupported __stuff in headers. Sure you could work without tooling like a caveman and you could print text to stdout using only the libc you brought with you, but most programs need to do a bit more than that.