There's no Battlefield moments is the problem. It's incredibly soulless and basic.

The gunplay is just awful, no gun has identity, they all just feel so similar. Point and shoot, hope the enemies dies before you do. No skill in it anymore.

The maps are so, so, so bad, they have zero flow and are clearly made to try and support every single gamemode, same problem BF4 had, but at least that game executed on a few.

Teamplay, as you say, is completely gone, they want everyone to feel special at all times rather than them having their moment. They could completely remove classes and it would make no difference to how the game plays.

And Arc... yeah, the falloff is inevitable, that's the most generic looter/extraction shooter I have ever played.