Celtics:
The celtic's problem is that they don't have a true playmaking scorer. Trae young is exactly that. Perimeter scoring and playmaking at PG will give Jayson Tatum a more score first role and they Celtics don't have to worry about the defense from Trae because they have so many great defenders already he can be hidden easily.
Hawks:
Hawks Get someone who is 2-way and still young, Jaylen Brown is going to be given complete offensive freedom with other 2-way players like Dejounte and Hunter he could really thrive. The hawks will need to make some more moves (collins, maybe Capela or Bogdanovic) to round out this roster but this trade seems to make sense as both teams can try something new while still trying to win as many games as possible
Who says no?