Randy is the most useless judge of any season (except for maybe Ellen), and he needs to realize that everyone wants him gone. Just go retire and live your life, dawg. He always has an agenda too.
Tyler spends most of his time in a stupor, using nonsense sayings and cursing. When he snaps out of it and becomes coherent, he's useful though. And he knows how to pick good contestants.
Still, this show should cycle in new judges every year since Cowell is gone.