I personally want my best players as involved as possible. That's why I like the fact that both Pjanic and Dybala are in positions to actually get the ball. The popular and in my opinion quite simplistic view is that we should have our best players as far up the pitch as possible. I don't think that is a good ideas as attacks usually start from the back unless you resort to long balls. If we suddenly sign a player like Pogba who can take that load of carrying the ball forward and creating for others Dybala can go further up.
I agree but I think the consideration for Dybala would be to not necessarily get him the ball as often as possible but as open as possible considering his main talent is a strike, not necessarily passing.
If he is the #9 then when he comes back into midfield we can have 6 or 7 players there (3-5-2 vs. Bologna in September

). In which case he finds an easy time getting open. If he is playing #10 then he *is* the midfield, so he's never open. There are only 3 players there and he is the 4th. Easily marked and he has to rely on first touch, quick passing, etc. Attributes that aren't his strength.
I will try to find some example of this situation where he is in a clear numeric superiority vs. Bologna and screen grab it.
Edit: We need to find this situation more often. Technically both CR7 and Dybala are strikers in this match but look at this position they find. I don't know if you necessarily need to play the 3-5-2 to find it but it helps to have two wingbacks who are on the last man to stretch the defence. And imagine Bernardeschi playing the B2B CM role instead of Bentancur in this picture. A player who can take up that space that Dybala leaves. It's a nightmare.
Edit 2: If you want 99% possession. No striker for the CBs to mark. You might not score from here, but you will have the ball. Is that really a negative thing?
Edit 3: If you want Dybala to be a playmaker:
I suppose this is more of an argument for a 3-5-2 than I thought because you get 5 midfielders instead of 4 and you get the wingbacks pinning the defensive line back instead of a #9.
You might also do this with a 4-4-2 where you just split your CBs and basically everyone else is in attack but that is a big risk considering Bonucci is isolated.
Although I think you can still incorporate Mandzukic in a 3-4-2-1 and have a lot of players in midfield as well. My main point is that Dybala should be a surplus in midfield, not part of the midfield.