It's not just ISA. If a competitor to AMD or Intel came out with a chip that requires recompiles, but is significantly ahead of them in a key metric, it would

It's not just ISA. If a competitor to AMD or Intel came out with a chip that requires recompiles, but is significantly ahead of them in a key metric, it would sell in the server market. But competing with Intel and AMD takes billions of research, and well, the design of modern CPUs is surely a patent minefield too. Just look at what's (not) happening with ARM servers.