New home HVAC system

i moved into a new construction home last year and when I had someone come out to put in the AC they walked the house counting the vents. Turns out i only have 3 return vents in the hole house. It is a 3300 sq ft 4 bedroom 2.5 bath home.

There is only one return on the second story in the hallway and two on the first floor, one in the main living area and one in a back room behind the kitchen.

He made it sound like the builder did something outrageous by not putting returns in any of the bedrooms.

Is my house doomed to poor heating cooling? The builder put vented over each bedroom door leading to the hall i assume to help air flow.