For me its not as immersive as previous games, especially BF1 which I think was the pinacle of audio design. That said, there are times when the sound is pretty fantastic when all battlefield elements are present, IE aircraft, tanks, building damage, etc.
I have had to enable Headphone 3D on windows and only then could I get spacial audio to work in game.
Still, its pretty great.
Regarding missing sound, this was really bad in 2042 where tanks would appear right behind you, no sound. So far, its not too bad for me with BF6, but I understand the issue as it can be frustrating when an object suddenly appears out of nowhere.