I think they really believed that Lillard would bring them the scoring threat on the outside that would free up Giannis in the paint - that it was worth losing Jrue to get that. But Lillard has been inconsistent and nowhere near as productive as he was in Portland, and often injured - and as a result he wasn't able to get the Bucks another shot at a championship. And I understand all the "speculation" because right now, Giannis is the only asset that the Bucks have that is worth anything. Nothing left to trade to build around him - so if he still wants to stay, they need a plan.