Originally Posted by
tdracer
It's more to the design trend of more 'open' cabins - especially on wide bodies. Individual air vents require a low overhead with the vents within easy reach of a seated passenger - a low overhead tends to feel claustrophobic and is counter to the open, airy cabin that most passengers prefer.
That explanation does not work for me because right next to the now absent individual air vents are the adjustable lights that also need to be within easy reach of a seated passenger.