Why can’t you see what cards someone doesn’t have when trading?

Trading is extremely annoying to me and I never initiate it because of this. My friends will offer me a wishlisted card, I have to offer them something completely random because they don’t have any cards of the type on their wishlist, and (unless I’m mistaking) you can’t even see what cards of the rarity they own and don’t own, so they always inevitably just terminate the trade. What is the point of this? It just makes almost all trade agreements fail because no one any any idea what the initiator wants or needs. At the very least, why can’t you offer the friend a selection of like a 3-5 cards they can choose from?