I completely disagree. If the Dubs had just let KD leave for nothing their starting five for opening night next season would look something like; Steph, Draymond, Damian Jones, Iggy (although I would have expected a great deal of load management throughout the season) and one of Alfonzo McKinnie/Jordan Bell/Quinn Cook. I think they would have liked to have re-signed Kevon Looney as well but because of their luxury tax issues he may have proved too expensive. Since Steph, Klay, Draymond and Iggy's salary already added up to close to 107 million and the cap is 109.1 million then the only route open to them to sign players other than their own would be the taxpayer MLE which is about 5.7 million for 2019-20. I don't think that starting five would scare anyone and to be honest may not even make the playoffs especially if Klay doesn't come back until late February/early March or later.
By signing Russell, the Dubs now have an excellent back court, Draymond Green, Damian Jones and the possibility of McKinnie/Bell/Cook as a fifth starter. I believe Looney will now be gone but he may have been gone anyway. That team should at least be competitive and more than likely make a run at the playoffs. When Klay comes back the Dubs now have a trade piece in D'Angelo Russell which could then be used to either bolster the bench or pick up another pretty good player depending on what is needed. If they make the right trades a run at a Championship could still on the cards.