I'm going to offer some suggestions as I have been pretty critical of BG3 combat. I realize huge changes are impossible at this point so my suggestions will be realistic considering the current state of the game.
1. Remove the current height advantage. If you must, reduce it to +1 and no more. 2. Remove acid, ice, fire ground effects from arrows and other elemental attacks (unless specified in 5e). Each attack offers a special condition so there's no reason to create additional difficult terrain. Fire does pure damage so it does the most damage. Acid reduces armor (it should just be a splash but whatever), ice slows you down, necrotic prevents healing...etc, so no reason to provide even more bonuses. 3. Nerf barrels and make it more difficult to carry them. 4. Bring back action economy. You shouldn't be able to disengage and attack in the same round. That's a core rogue ability and allowing any class to do so, takes away the reason to keep a rogue. Shove shouldn't be a bonus action either. Try to stick with 5e rules if possible. 5. Remove advantage just because you can move your character behind something. I don't mind if you use variant flanking rules so fighting two creatures (they should be in opposite sides but to make it simple just make it two creatures anywhere), they both get advantage to attack. 6. Food shouldn't heal. And if you must, only heal out of combat. 7. Remove the jumping sound effect or change it. Our characters sound like the Hulk jumping from far away when they land. 8. Remove dipping. Seriously, it's ridiculous. Flame weapons from candles? Additional effects are significant in 5e which is why Flame Tongue doesn't have any hit/damage bonuses.
Some people will like my suggestions and some will hate it. I just hope Larian takes a look and makes a critical assessment.