13 - 9 as a starter
8 - 2 since the All-Star Break and Trade Deadline.
I think that the simple answer is that the Jazz are very competitive with Dante Exum in the starting lineup while he's developing, despite having to play Jingles and/or Millsap as SG starter for most of those games. . .
. . . imagine how well he might do with 5-10 lbs of muscle, a better grasp of the offensive and defensive schemes, much better conditioning, Burks back and healthy, Tomic/Booker as the 3rd and 4th bigs (respectively), a shiny new rookie drafted 11 or 12, a free agent or two (as needed), Jingles and Millsap playing spot minutes as role players and continued improvement from Gobert, Favors, Hayward, Burks, Hood and Burke?
I think that the Jazz and Exum will be just fine letting him play while he develops.
I think he is gonna take a huge jump next year