double tapping / mashing to hold combo with a terrible accuracy (let's say 75-85%) isn't terribly hard, i've won many multiplayer lobbies by seeing if i can cheese certain parts to hold a combo and better score, meanwhile someone could have 99% acc and 1 shit miss at a difficult middle part that the other player mashed through and is heavily punished. I even saw this in a tournament which made me sad. FCs can still be very hard to achieve there's no doubt that I agree with you, but I really think the higher accuracy player shouldn't be punished in a rhythm game.
Get better 👍