That trade is about even. Makes the Cavs worse this year, but not appreciably worse, but they get a potential difference making rookie at some point down the road. Obviously they would rather keep Irving, but that ship has sailed and that would be a pretty good trade for them given that.
Suns get the star they have been trying to land for years and have 2 seasons to convince him to stay (which he might if Booker, Chriss, Bender, etc. keep developing).