[near]

That is true. There are however techniques software emulators can use like run-ahead that can get you lower latency than even the original hardware on a PC: https://near.sh/articles/input/run-ahead

The caveat is that it doesn't always work, and it makes the power requirements even more unbalanced. Some might also see it as a form of cheating to go below the original game's latency. If you want to match the original game's latency precisely, FPGAs are the way to go right now for sure.

[tediousdemise]

Run-ahead seems pretty cool, great technical write up. How would you compare this to the feature called frame-skipping that I often see implemented in software emulators?

[near]

Frame-skipping is just a speed hack of skipping rendering every other frame or so, and makes games very unenjoyable to play. It won't help with input lag at all.