Gonna have to disagree on this. Input parity is a big issue for multiplayer games.
Look at Apex, roller players complain about m&k being able to do certain movement tech, m&k players complain about the ridiculous aim assist on roller. People sometimes cheat by using the roller to have aim assist, while using macros to achieve certain movement tech.
Touchscreen vs m&k isnt even close to roller vs m&k. It’s really only fun for the person who has that advantage at that point. You essentially make it so that you get to have fun while everyone else doesn’t. Sure, it might allowed by the devs, doesn’t make it any less fun to play against.
To your point on ranked, not everyone wants to play that. Sometimes they just want to turn on their phone for a quick match.