MIPS is as close to a "real RISC" CPU as one can be, and it's "everywhere you don't look", but for reasons entirely unrelated to performance --- it's the choice of SoCs which are too cheap for ARM. I suspect RISC-V is going to become more popular in that market, although it's one which is already filled with various Chinese MIPS/RISC-ish cores that are entirely unimpressive.