The three teams are from the lore of the game. You're representing one of the three Grand Companies in battle.

Also of course a lot of people don't know what they're doing. FL is a daily roulette. Not to mention some people spam it without caring anyways. But you can win a 1v2 easily if your team is actually good.

You need two things.
A) Don't just sit back collecting points at the start while the other two teams build up BH. Too many people think that's winning and then they wonder halfway through why their team is suddenly outmatched by even just one of the other teams. Don't blatantly ignore objectives either but BH is important.
B) Callers in the chat and the rest of the people in the team being willing to listen to them and maneuver. If you get pinched then that's probably on you for people on your team not checking the map and calling out that it's incoming.

And it's entirely up to RNG whether or not your teammates are up to this or whether or not you end up against small premade groups that are better organized and so forth.