Modern CPUs are pretty low-level RISC stuff internally with x86 instruction set layered on top, right? Now, it would be interesting to see what would happen if

Modern CPUs are pretty low-level RISC stuff internally with x86 instruction set layered on top, right? Now, it would be interesting to see what would happen if someone started making desktop-class cpus with the ARM instruction set instead of the legacy x86 instruction set.