Elebhra
Using shove to prone a target is only really worthwhile if you are guaranteed to make 2 additional attacks at 50-65% hit chance before advantage and that assumes 100% chance to prone?
What about forcing a tough enemy to have to get up so they use half their movement and thus can't get close to your wizard?
What about knocking prone so a rogue can get sneak attack and then dart away without AOO from a serious enemy?
What about a fighter knocking prone and then retreating without fear of AOO from a serious enemy?
What about knocking a high AC enemy with low Athletics prone so your whole team can melee beat the crap out of him/her with advantage and then fall back? Can't hit that AC 22 bad guy? Knock'em prone fighter with +7 Athletics.
Knocking prone has MANY strategic advantages.
It's not just about advantage for 1 person for one hit.