I don't think that's it. I think there is a strong perception that this roster has already reached its ceiling. There's a big difference between winning 48 games when you have two 20-year-olds named Durant and Westbrook on your roster, and winning 48 games with a bunch of second-tier mid-career guys who bought into a team concept because they were happy to have the opportunity.
Well, I disagree that they've reached their ceiling, but even that's not my point.
My point is that two years ago, Dragic was an OK player. He finished the season averaging 20+ points, shooting great percentage from the field and from the three, ended up on the third all-NBA team.
Last year, Plumlee was a nobody. Now he is a solid role player, even if we assume he reached his ceiling (which I think is a false assumption.)
Suns turned Jared Dudley into Eric Bledsoe. Now, I am not a huge Bledsoe fan, but he's an asset. At the beginning of last season, I was pissed that the Suns didn't dump the Morris twins. Markieff appears to be a real NBA player now. At worst, he is a good back-up PF.
Green was a nobody. He looked like a solid shooting guard to me. (Yes, I realize he's had good seasons before, and we don't know that he is going to keep playing well.)
Goodwin, at least showed some promise. Didn't see much from Len, but we all knew Len wasn't going to be a factor this year.
To me, that is a very nice step in the right direction. Suns now have some assets. They will keep adding assets, and having assets is what allows you to trade for these "Stars" or "Superstars" or "Franchise players" or whatever we want to call them.