Pjanic had to go indeed. He was regressing and it would have been the last year of his contract.
Did we get the better deal? It's yet to be seen.
What is clear so far, though, is that we got the worse player.
Even in his last two seasons in Juve, when Pjanic wasn't good at all, he shat all over this Arthur from 2020/21. In every single offensive, every defensive, and all but one passing stat, he was (much) better than Arthur.