You’re the problem not your teammates.
If you are the person telling your teammates they are trash, typing “gg no heals” in the chat, saying “dps diff”, telling someone to switch off a character before the game even starts, I have news for you bud. You’re the problem. I don’t care how much you think you are carrying. Your toxicity is only going to make the game harder to win.
I will never understand how people don’t get the concept of being nice or at minimum tolerant of each other makes you more likely to win. As soon as you start being negative and create a toxic environment for your team, the likelihood of you winning goes out the window. People are less likely to switch off of a character if you tell them they are the worst insert character here you’ve ever seen. You can give constructive criticism or ask for what you need, and not be toxic about it.
Edit: Not being able to take accountability and accept that maybe your character isn’t working with the team comp is also toxic. You going 2-18 isn’t your healer or tanks fault when your other teammates have 4 deaths each. Still arguing with someone who is too stubborn to change after politely asking isn’t going to help either. So might as well not get into a screaming match.
At the end of the day it’s just a game and you can’t control your teammates. Being kind/tolerant is better than wasting your own time and energy on adding to the toxicity. Best you can do is focus on what you could be doing better instead of how “trash” your teammates are.