ARM64 is what Intel would design if they learned from the lessons of x86 and got a chance to restart.
It'd be fun to throw together a modern CISC-V or something that does a better job than x86 from an instruction encoding efficiency perspective, and see how it stacks up against modern RISCs.
It'd probably be about the same since the combination of microcode and macroop fusion makes RISC and CISC essentially the same thing internally. You're basically just trading complexity of the instruction decoder for code density.