Right, but it's not just pushing a button to get the recompiled code, there's still translation work to be done. Crucially, a framerate will need to be chosen, so you can just choose to base the framerate on the processing done.

Sure, the ROM is "original" but I'd argue that accessing the source code - or an analogue to it - is a more fundamental way of archiving the original, since without that source code we don't have access to how it was originally made.

The point is not that it competes with ROMs or replaces them, but it adds to them and makes the archive that much more complete.

Also for games where emulation doesn't work or isn't practical, recompilation can allow us to maintain games that otherwise couldn't be.