Bots
I have no idea what category to put this under but since they're masquerading as players this seems to tentatively be the best. I'm losing my mind playing vs bots game and getting sometimes 1 but usually 2 bots on my team that just go stand in the jungle and occasionally int to camps. It makes the games harder than they need to be and it's really frustrating especially when some of the only real people on your team are new and don't know how to not int. It's doable but sometimes you as Trist and your mid lane Teemo have to legitimately 2v5 the bots all game because your Ahri dc's immediately.