He can pull it off, but it's not his style. He did it with Cagliari occasionally as well. He needs to become more dangerous in the box basically.
^ IMO this is correct and applies to not only Barella but Brozovic and Sensi as well.
Brozovic has 20 goals + 19 assists in 154 apps in all comps. If you look at those goals, you can see there's a relatively cultured player there who can score from distance from time to time or finish a chance from time to time. But as brehme says, it's not his style to do it any more than he is currently doing. Brozovic can go entire matches without attempting a single shot. That's fine. Despite his character, he's a pretty intelligent player so let him attack when he sees fit because he can pull it off from time to time. However, try to change him, get him to shoot more and attack more and I believe you'll pull him from his comfort zone into a role where he won't succeed.
Barella isn't much better tbh. He scored one goal last season - a cross deflected into the net. The season before that he scored 6 goals. 3 of those were penalties, 1 was a deflection which wasn't even on target, 1 was a howler by Donnarumma. Only one was any kind of good finish from open play. I haven't watched Barella as much as some of you but I've never, ever got the impression he's a particularly potent goal threat whatsoever.
As others have identified, the only natural goalscorer we have in midfield is Nainggolan - and he seems persona non grata anyway. Vecino has scored a few nice goals, all from about 1m away from the net. Gagliardini lacks composure in front of goal. I won't even dignify Joao Mario and Valero with a mention because those two wouldn't be a goal threat if they were playing against children in wheelchairs.
As it stands, I don't expect anyone in midfield to contribute very much to our goal tally. They can all score from time to time, but it's simply not in their DNA to play this way consistently and with high quality. We simply don't have a Lampard/Hamsik/Vidal type player to make late runs into the box and finish chances etc. Nor do I believe any of our current midfielders can be converted to play that role at a high level. This is a problem, and it's why I've wanted a goal scoring CM for several seasons now. Nainggolan was supposed to be that guy but he was either over the hill, or injured and now unwanted by Conte.
I'm using the evidence of what we've seen from these players to discern what kind of potential and skills they possess. And as far as I'm concerned, our current midfield (minus Nainggolan) does not even come close to juve's 2011-14 midfield in terms of attacking. You can not compare this side with Conte's juve.