In general, shoving is a useful mechanic to counter ranged characters who would otherwise have too much advantage from heights (since there are no abilities like Teleportation in DOS2 in BG3).
Larian’s high ground bonus is home brewed as well, but after it was nerfed to just giving +2 I like it.
The reason I like it now, is that +2 is something you can deal with in a variety of way. It’s a bonus, but not an overwhelming one like it was with free advantage. While being able to push enemies down is good, making it more situational (like only if they are within a vicinity of a cliff) wouldn’t hurt, as there is a variety of spells and items one can use to counteract the high ground bonus. Push being as powerful as it is, makes it the best option available at almost all times, which is boring from an instrumental play point of view.
I don’t hate push in encounters without major drops - though I think push is still poorly balanced: solid damage and high ground advantage does make shoving enemies a bit of a no brainer option, but it doesn’t dominate the battle’s outcome like in some of the later encounters. Still, I think full attack action cost would be a better fit, than a bonus actions.
In underdark and forge, though, push is inexcusable.