Why don't trades work the same way as giveaways?

I'm having a really hard time with trades through steamgifts - it's difficult sifting through the trades that people have bumped from a year ago or more to find new trades. When I finally do find one, it takes considerable effort trying to come to some sort of agreement and it often ends up going nowhere.

Why can't we just create a trade (Offer), drop our key/link in it (hidden)/just the name of the game if it's a gift, people can submit offers with their key/link/offer of a game. We can either then accept or reject and the keys are automatically swapped or details of the user are shown so you can trade through steam. Also it would be much easier to search through.

Seems like a wasted opportunity when the underlying system already exists for giveaways