@Lancelot_du_Lac I wouldn't say BF3 or 4 had much teamwork either.
BC2 did have a good chunk of players playing together. But that was due to small 12v12 or 16v16 format. If a squad was working together, they could cause alot of trouble for the enemy team. So it made sense.
BF3 and BF3 is where people began going 1 map army because it was simple and there was no point in going with a squad. You were most likely to get wiped by a single jet or overrun by the enemy herd.
Introduction of the assault class with defibs and health didn't help the matter. Everyone ran with the best and most overpowered weapons (Hello BF3 M16A3 and AEK-971) with M26 Dart + med bag and be a happy 1 man vs 64.
BF4 solved alot of the balancing issue, which made "teaming up" no so important. Vehicles weren't too hard to deal with, unless it was some really sweaty heli pilot on Siege of Shanghai or Dawnbreaker. This again made going solo assault and farming tons of kills very easily and profitable for the most part.
Since then it kept going downhil.
BF5 did a decent job promoting squad play. It was the first game where I saw randoms actively trying to stay together, asking for orders, reviving etc.
2042 threw it all in the bin.
And as you mentioned, people don't really care anymore. Which (I think) is why Battle Royal games are so popular. There you don't have to rely on 30+ other people to actually play the game. Everyone is for themselves.