The Phoenix Suns are still in rebuilding mode. Of course they are, and no one disputes it.
But so are at least 20 other teams in the NBA. Maybe 25.
All 14 lottery teams, plus at least half of each season's playoff teams go into the summer with the intent to improve their roster significantly for the next season, which means that nearly every player is available in trade or may be replaced in free agency. That's just the way of the NBA.
No, the Suns do not have a core around which to build a perennial 50-60 win team.