If Dybala ever dreams of winning the Ballon D'or, he won't do it at Barca as funny as it sounds atleast not by moving immediately.
Neymar is moving away because he doesn't want to be Messi's sidekick and rather spearhead another top team which would also increase his chances of winning the Ballon D'or + more money from image rights etc etc. Tbh financially speaking, it's a good decision on Neymar's part.
If PSG can win CL and if he can become a big part of it, his decision to join a club in an 'inferior league' would be vindicated.