I don't have a ton of experience with the Battlefield series, but has this problem of nobody playing their damn class always been an issue? Why do medics just stand next to you when you're clearly low health and asking for heals? Why don't support guys hand out ammo boxes like they're candy to anyone and everyone within range? They're rewarded for it, it helps the team, it will help your individual score....why don't they do it? I can understand a medic avoiding a revive in a hot spot. If I put myself in a bad spot and get killed I don't expect a medic to do the same stupid thing that got me killed. But you can see the health of your teammates, if I'm low, help a brother out! I just don't understand.
Online gaming has taught me the idiocracy is real. There's been a massive decline in teamwork and general camaraderie over the last 15 years or so, with individualism really skyrocketing. It's at odds with the core tenets of Battlefield.
A good squad can easily win the game for your team if you just PTFO and revive each other. You don't even need to be top tier shooters, just average.