Ok, the topic at hand is silly, bit there is a merit in the fact that many containers (not just vases) are empty or contain junk. I suspect the reason is partly because (at least this is my understanding) there supposed to be some sort of more complex crafting system in BG3, which Larian cut at some point for whatever reason, and a significant part of loot found in vases, boxes or crates are now junk, not something useful for crafting. I guess crafting is a feature that could potentially find its way in Definitive Edition.