Indeed. Motta's career at Juventus has just begun, so it is not apple-to-apple when compared to Allegri who has been Juventus manager for years. So we cannot compare who is better and who is not. What is clear is that Allegri contributed several top Serie A 5 trophies, the Italian Cup, and so on. In the past, he was actually very good. However, it's all over and now it's Motta's turn who has just begun.
Now it's time for Motta to work and start his career at Juventus. At least, Motta had good experience previously at Bologna. And in the first 3 matches, Juventus' performance was quite good. So, we just have to wait and see what happens next.
I also think it is not fair to compare Motta new job at Juventus to Allegri old one. Allegri did great job in past but we can not expect Motta to be just like him. Motta has chance to do things his own way and make name for himself. He has experience from his old job at Bologna and Juventus has started well under him. Let's give Motta time to figure out his own way of doing things. It is exciting to see what will happen next for him and Juventus.