I don't care for the new modes, but everything else has been pretty good. The new map is actually quite good (although badly ruined in Escalation by tanks camping in HQ, but that's on the players, not the devs). The new rifle is pretty niche but really good in that niche.
And more generally, the game is more fun that it's been since release: the gunplay feels good, the land vehicles are well balanced. It's a bit more iffy for air vehicles, but still overall the game is in a better place.
Don't get me wrong, there's plenty, and I mean plenty to complain. But saying the game failed to deliver content or fun is simply not true. Let's remember for all the incredible toxicity of this forum, the game is doing fairly well. It may not be for you, and that's fair, but you should have realized that way earlier, a refund at this stage is really unlikely.