I rarely have these issues. I actually heard the “Hey, I’m misssing a lot of shots; can I go DVa?” the other day. I’ve also said it myself when I fill DPS. It does happen.
If you don’t want to work with aggravating teammates there’s not a ton you can do. You only fully control yourself. Also if McCree son’t listen tell Rein to press W. Often I go (since healer) “Rein, I got you. Push forward! I’m (bleep)ing all over you! Swing! Swing! Swing batter! You have all the Moira (bleep) you can need!” etc snd you can spur them to action. A lot on players don’t trust each other. Tanks fear dying from no heals so I reassure them they’ll have plenty but I cannot do much from behind the choke nor can Rein or anyone else.
It might be annoying but often communication (serious, non-finger-pointing, some praise, a crude joke, asking questions, etc) goes a long way. Sometimes they just want a pep talk. Or their hand held. Or to hear some tale of success against seemingly insurmoubtable odds. Maybe they need the whip. Whatever works. But I’ve learned asking for a switch rarely works. Instead “hey that pharah is an issue. Any wanna dva? Or maybe ashe?” Or “that shield is an issue. Any wanna Junkrat or Roadhog or something? Something with big, aoe?” and folks are WAY more receptive to that. Why? One: they feel like a hero. Two: no one implied they were bad/trash just something will work better. Three: no one blamed anyone. No one gets defensive or fights. Interpersonal skills are a key part of the climb weirdly enough.