Performance is just about the number of $$ spent on hiring good engineers. At least several hundred million for something competitive with current Intel / AMD /

Performance is just about the number of $$ spent on hiring good engineers. At least several hundred million for something competitive with current Intel / AMD / Apple and those companies spent into the billions. Mostly it doesn't depend that much on the exact instruction set. It is possible to make a bad one, but x86 actually managed by more luck than anything to avoid the worst mistakes -- unlike, say, VAX or 68020. Arm64 and Riscv64 don't have any of the bad features that make performance hard, so if someone competent tries with either one then they'll succeed. Obviously Apple and Qualcomm in the Arm world, and there are something up to half a dozen well funded companies with good experienced engineers in the RISC-V world.