Not only has Sancho failed to live up to expectations for his hefty transfer fee, he's even tarnished Manchester United image by clashing with the manager. His talent has been diminished by his temperament, so it's understandable that Manchester United would want to cash in on him immediately, even if it means incurring a significant loss. Juventus would certainly be the lucky club to acquire Sancho for a lower price, and I imagine Chelsea would be furious, especially with Sancho reportedly willing to take a pay cut. In Serie A, Sancho might rediscover his best form, similar to his time at Dortmund.
I was very happy to hear that Sancho was willing to take a pay cut to join Juventus. This means Sancho is still thinking about his career advancement. Honestly, I'm very happy to see Sancho play because I think he has everything, but unfortunately, the feud with Manchester United management has made his career dim.
Manchester United has no other choice but to sell Sancho because the bad relationship is irreversible, and it would be detrimental to both parties if it were forced. On the other hand, Juventus would be the team that would benefit most if Sancho could return to his peak form.