Yeah, defense does matter... so do games missed.
I think Jaylen is the most talented offensive player on the Celtics, and under the right circumstances on a team that pushes the ball and looks for him more often he'd be devastating. Unfortunately every time he's needed he's injured or playing injured.
I checked, he's not listed in the top 10 most often injured players in the NBA, but he's certainly is in the second tier. And for that reason, before he breaks into the top 10 where Kyrie and KD live, it may be time to let go.