Maybe, but even if that is the case most of the huge mistakes var was apparently bought in for are fouls and handball which are subjective as well so you could argue that VAR isn't really going to solve anything while causing a lot of disruption.
The only other bit of tech I'd like to see used, was one that was being discussed the other day and that's for encroachment in the penalty area/determining whether a foul is committed inside or outside of the box.
So basically the same as goal line tech, but used on the 18 yard line.