Well, I can't tell about others but I mean... I know that a border is right there. So I position myself on the opposite side of the edge, they mostly won't even try the shove. And a simple solution. Don't go full group combat, Separate companions, position them first. Then start the combat, use the hiding outside of combat companions to kill the ones that can be more dangerous to use it on you. I know it seems complicated, but is easier than it sounds once you start doing it more often.
This looks very theoric... But the entire map is build arround verticality. You always have to go higher not to have disadvantage and a lot of area does not have a side you can't be pushed from (blighted village roofs + next to the mill, gate of the goblins camp, outside the goblins camp, gnolls boss, giths, ...)
On top of that everyone does not play ranged characters so you just have to go where your ennemies are... you know, usually higher on edges...
About your repetitive strategy no, thank you.
I'm usually playing with fighter and melee classes. I don't want to ambush every ennemies. Combats are ridiculously easy if you ambush them all the time and it's so boring to deal with the chain and the turn based mode to position your companions.
The AI really hates moving through surfaces effects, so grease or web or what have you can slow down approaches. Flaming sphere cannot be pushed or manipulated in any way by the AI, so that can also do something. And of course it's reasonably hard to push a character with proficiency in athletics and 20+ strength from a potion. There's also hiding and potion of invisibility. Mage hand is mostly useless, but it's still a "creature", it takes up space, and it costs an action to kill it.
Oh yeah, all this to avoid a too powerfull bonus action. Unrealistic suggestions to prevent being shove.
But yes, it is very strong and what really takes it over the top is just how far people will fly. Reduce it to a default of 2-3 meters horizontal distance regardless of fall distance and suddenly it's a whole different thing.
I'd say 1-2 meters rather than 2-3 but anyway... agree with reducing the distance.
But it would be better if it was an action too.
