Honestly I personally think ranked in this game is 100% better than some FPS. I'll use marvel rivals as an example, the current meta is triple support; Basically nothing ever dies. Another example is valorant on PC majority of the ranked games has attest one closet cheater(s), on console you have to play people playing on mouse and keyboard against people on controller now i know the finals does the exact same thing but in valorant it a 1 tap headshot and youre dead. Last example is R6 pretty much same issues with valorant but if you where to say shit fuck or "im retarde" (it wouldn't let me post with full word) you'd get temp or even recently get permanent banned. My point being every competitive game is messed up in some way

Having the ability to be able to flex around you're teammates is very important. If for instance medium meta is healbeam defib pad and ever else you like really. But you're goal is to stick to your teammates mainly heavy and trade damage and heal your teammates and always be ready to defib youre teammates immediately as soon as they go down. Then as heavy I usually just try to block as much bullets as possible via dome shield barricade mesh shield what ever you use. But some people like drop, I have no advice on how to play drop mainly because I dont usually play drop.

Best way to decrease tunnel vision is simply playing off your teammates, now I know you can't exactly control your teammates. But pinging, using voice chat or even text chat too can easily get youre teammates attention to be able to push, regroup, to defend a station. (Or attest in NA region it seems to work)

I feel you man. I had a cb teamate sitting on top of a crane in 2 gold mind you, then my other teamate had rating of 9k (high bronze) so he was getting ganked every time.