Yeah, MIPS eventually supported SIMD instructions and the MIPS16 short-length instructions. I'm sure other things were thrown in there. Other instruction sets inspired by early RISC also added lots of things.
Most have stayed true to the fundamental separating memory instructions from arithmetic instructions. What makes an instruction set CISC, in my opinion, is allowing memory operands in arithmetic. Most RISC instruction sets also provide lots of registers to avoid reuse. The idea is generally that the compiler should be responsible for optimally scheduling instructions. But then, modern RISC are usually out-of-order processors anyway.
Most have stayed true to the fundamental separating memory instructions from arithmetic instructions. What makes an instruction set CISC, in my opinion, is allowing memory operands in arithmetic. Most RISC instruction sets also provide lots of registers to avoid reuse. The idea is generally that the compiler should be responsible for optimally scheduling instructions. But then, modern RISC are usually out-of-order processors anyway.