2. Cannot let talent walk out the door
Jalen Brunson is the biggest and most egregious example, but the Mavericks have been letting skilled players leave for zero return since they acquire Luka Doncic in 2018.
Dallas traded Harrison Barnes for virtually zero return at the 2019 deadline. They swapped Seth Curry for Josh Richardson, only to let J-Rich go for nothing one year later. Dallas traded Delon Wright and two second-round picks for 29 games of James Johnson. They sold low on KP, and even traded two starters for Kyrie. Each of those moves adds up as the Mavs lose a small amount of talent from their roster. Eventually, it becomes a massive talent drain.
How much better would the Mavericks be with Brunson, Barnes, Curry, Dinwiddie, and Finney-Smith over Kyrie? It is impossible to say, but they certainly would have a deeper roster with more avenues to improve.
Talent wins in the NBA. Every championship team since the 2011 Mavericks had at least two All-Star caliber players on their roster. Dallas currently has Luka Doncic and Kyrie Irving, but they failed to make the playoffs because the franchise kept slowly losing talent and depth from their roster. The Mavs must learn from this and figure out ways to improve their roster with every transaction.