"I think that a system that shows if the player is a good teammate or not (like if someone doesn’t help his teammates or dc after getting knocked) is important as that would generally improve the experience."
How would it improve your experience to know definitively that matchmaking is going to screw you over? You already know that it will whether it spells it out for you or not. Apex matchmaking has always been this way and it always will be. The only solution is a full stack, and that, I can assure you, will bring its own set of problems.
"third parties... happen TOO OFTEN."
They happen exactly as often as you allow them to happen. No more, no less. If they're happening to you a lot then the solution is for you to look very carefully at where you're dropping, where and when you're rotating, and to plan more effectively. I readily admit that if you solo queue then this kind of planning is impossible. Randoms will do what randoms will do. Trying to get them to play smart instead of hard is like trying to herd kittens. Nevertheless, it's a multi-team game. Third partying is baked into the pie. If it's happening to you then it's on you. There are players in this game who never get third partied and it isn't because they're lucky.
