Isn't Intel still the primary supplier of server CPUs? (as well as windows?)

They're taking a beating, but I feel like every few years we hear an "intel has fallen behind", and then they dust themselves off and are at the top again.

Though Nvidia can charge a huge premium for GPUs, those machines still need a CPU (if I'm wrong, please correct me).

Is anyone building ARM based servers? It looks like Intel has fought back against the Arm on Windows battle, and possibly won with their newest power saving Ultra 2s.

Do they really need to beat Nvidia?