We haven't sent them that much of actual material and most of that is outdated. A lot has been promised but deliveries outfit scheduled years from now. Money is useful but you can't shoot it, and a lot of Ukrainian capital is lost because of the war. And the most important resource, soldiers, is the one thing we can't send them. And Russia can just conscript as many as they want.
And it's Ukraine itself that wants their territories back, including Crimea and Donbass. Making it hard to negotiate. But also understandable, once you start giving in, you're giving Russia an incentive to do it all over again and capture now territory.