I don't see them as competitive with ARM and RISC-V.
The last I heard of MIPS was some Chinese-fabbed chip that used the unencumbered set of MIPS opcodes--probably MIPS II--and a mostly-GNU OS to build the only computer on Earth (at the time) completely free of patent or licensing restrictions. It sounded like a stunt then, and I haven't heard anything about it since, so it probably was.