The Beal move was such a team killer similar to the Lakers trading for Westbrook. Not so much a knock against Beal/Westbrook but paying max money for a player that has terrible fit with your other 2 stars and trading the rest of your assets/role players to do it is just brain dead management.
When the Suns lost to the Nuggets last year they actually won the most games against the champs of any team. The issue was that once the insane shooting from Booker stopped they didn't have the defense to slow the Nuggets down enough. So why would you then go and trade for a shooting guard that doesn't play good defense and give up your only good point guard to do it?