I believe that they could fix jump within the existing framework without too much work.
1. Remove jumping up onto raised terrain: They already have climbing rock faces implemented, a climbing spot for areas that were jumpable could be added to those sections that are basically jumpable stairs at the moment, but they could leave the ability to jump down off of high terrain and risk fall damage.
2. In combat, remove jump entirely: replace with a disengage button per 5E rules
3. Leave horizontal jumping in the game outside of combat: this way rivers and bridge gaps etc, can be crossed, and doing so would alleviate the need to drastically alter terrain.
You should be able to high jump though, just not to surreal heights. In 5e a character with 10 Strength can jump 3 feet high and a character with 16 Strength 6 feet high. Very reasonable. Lae'zel is jumping what looks like over 15 feet high in BG3 so Larian effectively tripled the high jump distance. It's not as silly and cartoony in PnP.
And why do we have the Athletics and Acrobatics skills if you don't have to climb anywhere or basically ever use them? There could be Athletics / Acrobatics checks when you're climbing difficult or steep terrain in combat to give those skills a purpose and to make the terrain more tactical (i.e. require actual skills to make the most of it). Relatively easy checks but fail and fall down and waste movement.
We can't remove jump in combat since it has tactical value there, getting over surfaces and chasms or streams. But jumping should definitely trigger an AoO if you are engaged to an enemy. And be a separate action from Disengage.
