The highlight button doesn't have any logic currently (some containers but not all of them).
It does seem to have logic, though a gamey one and I appreciate a lot, and wouldn't want it to change (I don't mind for highlight all junk button, but I would prefer to keep the one we have one).
D:OS2 highlighted all interactable items - something I nicknamed in my pre-BG3 D:OS2
feedback post item diarrhea - you enter the room, press highlight, and your screen get covered by text boxes of every painting, sheet of paper, ink, chest, remains of humanoid body, random pieces of furniture etc. etc. As far as I was concerned it didn't highlight anything, as it just listed every item in the room no matter if its important or not.
BG3 seems to limit it's highlight option to important stuff - so you can see at a glance what is worth interacting with and what is mostly a window dressing, that you can use to your advantage if need be due to the systemic design of the game.
Maybe the game could have a highlight outline for every interactable object, but keep text boxes for important items only?