What I do is inspect my group mates before the key starts, if I think say, the healer, is under geared ill say “hey I don’t think we will make it with this healer, but good luck with the run” and leave before the key starts so I don’t ruin someone’s key. If you’re getting part way into a run before realising someone is overestimating themselves, that’s on you. The only excuse for leaving a m+ early is if you join a timed key and it doesn’t time