1. Not having a point guard
It speaks volumes that having Isaiah Thomas on the Suns' bench as this team were getting swept is something that actually happened. Take nothing away from Thomas, it was fantastic to see him get another opportunity in the league, albeit a small one as the Suns never really used him once he was signed for the rest of the season.
But Thomas was only there in the first place because the front office thought that Booker and Beal could share the ball-handling duties between them. Perhaps they could have - and by season's end the flow between the two was a lot better - but the injuries to Beal early on hampered the chemistry they were trying to build.
It got so ridiculous that coach Vogel mentioned maybe deploying the barely used forward David Roddy to run the show for periods of the game. A not so subtle dig at the front office for leaving him in the trenches without an established table-setter for when things started to get ugly out on the court. Which they often did, and which is also another reason why turnovers were so high.
In a season of what ifs, not having a point guard after the departure of one of the greatest to ever do it in Chris Paul really hurt the franchise. It was most evident in the playoffs, as the Timberwolves had an old head in Mike Conley Jr. who was able to slow them down and get them into their sets as the games got tense. The Suns need to find their version of this next season, it's their highest priority.