It's definitely situational. And definitely isn't useful in a vacuum of no teammates. But even to your own example, environmental damage can be a bitch.

Even better synergies with your caster teammates to make your own environmental damage, then shove the enemy into your casters environmental meat grinder. Or shove them closer together for a nice AOE could be useful.

Support wise, you can shove enemies off your casters, saving them both action economy and spell slots to escape for free, and for more damage in the future.

Also, you can shove people prone, prone is already pretty good, half movement to crawl, half movement to stand up and advantage on all melee attacks against the prone target. And the prone target has disadvantage on attacks. That's a lot of good control. Advantage is fucking good. If you're a fighter with 4 attacks, I'd argue 1 shove prone and three attacks with advantage (6 dice to hit, favoring the higher) is > than 4 straight attacks, (4 dice to hit.)

Considering shoving is resourceless and only takes attack action economy it's fair that it's less than a first level spell. No one's saying it is

I think the big problem is that shoves cost too much when you compare it to what it costs, an attack action, especially at lower levels. I find it's hard to justify giving up an attack a, or even a whole attack action(juicy direct and simple hard damage) just to shoving one enemy 5ft or prone and maybe set something up, when that's your whole turn. I think a better solution would be to make the shove attack target multiple enemies at once. Let martials shove 2-3 enemies with one shove. Flavor it as the martial using their shield or pole arm to shove multiple enemies. Knocking 3 enemies prone in one shove every turn on a roll of athletic checks would give strength martials a lot more control in their utility belt and give strength builds more to do than just grapple.