Aiming was not a core mechanic in the first two Fallouts. It’s actually an underused mechanic because one of the best traits disables it. VATS lasily tries to combine the aiming system and the turn based mode of the originals and fails. Fallout 4 did VATS better.
Bethesda admitted VATS was included because they couldn’t get a hang of guns in thier engine.
New Vegas devs disliked the implementing of VATS and improved the gun play in several ways.
Fallout 4 did VATS better.
Again, just another opinion formulated as if it is fact. To me VATS was not usable in 4 but 3 and NV did it perfectly