I suppose Larian was looking for a way, to reimplement their mobility skills from D:OS2, and giving everyone “decent” jump was the simplest solution to make “flying” available to everyone.
Which is not something I am fan of just as a design principle that ripples through the whole design. The cool part of DND spells and skills is that they allow to do stuff that is otherwise impossible. So everyone in BG3 could compete in olympics (not to mention their throwing range!). But wouldn’t it be cooler if characters unique abilities would allow for that? Gythianki’s jump, fly, spider crawl, Misty step etc. I hate to bring the-other-game, or really any other RPG with exploration, but isn’t it cool if we can do something cool because we invested in something unique to us (speak with animals, speak with dead, movement abilities) rather then allow everyone to do everything regardless of choices?
Most of the characters can't actually jump all that high. Laezel can, but then she also jogs around while carrying a backpack that I couldn't climb a flight of stairs with.
Obviously the combination of those feats, jumping like a kangaroo on steroids while carrying a backpack is utterly cartoonish, but I think the bigger problem is how exaggerated the jump animation is. A loud yell, a weird angle on the jump, probably too much range at higher strength levels, and a Hulk style heavy landing. That is over the top and feels weird.
As for other RPGs, how many can you think of that really did a whole lot with 3D verticality? Morrowind springs to mind, but the jumping in that game makes BG3 feel a bit lame by comparison. Morrowind let you jump so hard that you could crash into a ceiling and be stuck there for a second because of your inertia. You could jump onto the roofs of houses without magical aid and with a tiny bit of magic you could literally jump across city blocks. And with a bit more magic, you could start crossing the continent in a few leaps. Now that's jumping taken to the next level.