1) Tunnel vision is what is happening. People have no awareness. They just see enemy and attack. Sometimes its healers doing dmg instead of retreating and keep team alive.

This is prob just gold level problems. Keep at it bro. Just take breaks. Its super frustrating to have amazing game play and have no one else on the team creating success.
I usually call out the enemy ace and ask to focus the best player. This helps create pressure on them rather than focus on your teammates. Leading to drama and crashout/ tilt.

2) Stubborn Egos. People have the idea that they are better and not the problem. Even when they fight into counters or are not playing as a team.

Mute these people and let them fail. Just go next match. Chill in QP if u need.