As you are obligated pay them if you make money of a game. (i pretty much just simplified what the terms tell you to do) If you don’t and you try to cheat it, then pretty much you are doing something illegal and a law suit would be filed against you where you would lose the moment you would put your foot inside the doors to the court room and you wouldn’t be able to sell the game at all on steam, g2a etc.
Besides i don’t see any reason to why you shouldn’t pay the 5% as if it wasn’t for The engine you wouldn’t even make any money of the game.