I think given that BG3 needs to work seamlessly as a single and multiplayer game, and a multiplayer game that supports party members acting adversarially to each other, separate inventories are necessary.
Encumbrance can be a bit annoying, but can you imagine the vitriol that would echo across this forum if characters could carry unlimited explosive barrels at a time?
True! Just remove encumbrance, then. That way I can carry all my loot (and I don’t really care if other people want to carry barrels)!
