If you have a tense trajectory it is much easier to hit. That is why "effective range" in tank and AT guns are usually measurable by a certain value for the trajectory drop of the round.But actually hitting the target was as much down to the sight and the gunner as it was the gun
That is also the reason every tank gun todays is a high velocity gun despite computers, sophisticated FCS. A faster round also makes possible to have higher rate of fire and change targets faster.