ARM was never a "speed demon"; it started out as a low power small-area core and clearly had more complexity and thought put into it than MIPS or RISC-V.
Over a decade ago: https://news.ycombinator.com/item?id=8235120
RISC-V will get there, eventually.
Strong doubt. Those of us who were around in the 90s might remember how much hype there was with MIPS.
I don’t think you remember, But the first Archimedes smoked the just-launched Compaq 386s with a dedicated 387 coprocessor.
It was not designed to be one, but it ended up being surprisingly fast.