That's true, the small differences between a pragmatic "accurate enough" emulator and real hardware can matter for speedrunners. The difference between real hardware running at 60fps and a principled cycle-accurate emulator running at <0.1fps would matter more, though.
For the SNES and earlier it's feasible to have exceptional accuracy and still usable performance, but for anything modern it's just not happening. Imagine trying to write a cycle-accurate emulator core for a modern CPU with instruction re-ordering, branch prediction, prefetching, asynchronous memory, etc, nevermind making it go fast.
I think the cutline can be moved to the original PlayStation now.
>but for anything modern it's just not happening.
Which arguably explains a cultural rift in arcade emulation circles. MAME's philosophy is about cycle-accuracy, which might work for bespoke arcade hardware up to early 3D systems, whether they're bespoke (such as Namco's System 22) or console-derived (Namco's System 1x series, which all derive from the original PlayStation hardware) hardware. For newer arcade titles, which are just beefed period PCs, such kind of emulation (philosophy) would not be suffice for gameplay.
For the SNES and earlier it's feasible to have exceptional accuracy and still usable performance, but for anything modern it's just not happening. Imagine trying to write a cycle-accurate emulator core for a modern CPU with instruction re-ordering, branch prediction, prefetching, asynchronous memory, etc, nevermind making it go fast.