Yeah, Rabiot switches off way too often but that also happens to Bentancur more than ever before. Last season Bentancur had shown he can read the game and anticipate things pretty well. That's one of the reasons why he got to play as a DM - he'd give extra cover for the defense and he'd release the ball quicker than Pjanic. Otherwise the latter is always a superior player.
My guess here is: the players don't really understand what they are supposed to do and when. When to run, how to position yourself and which patches of the pitch to cover - that's on coach, that's called organization. You learn the system by learning the patterns.
This problem in general shows very well with the rest of the squad as the team quite often tries high pressing but they're applying it very badly. That shit is on Pirlo too.
But yeah, the players aren't helping Pirlo too much at times. Then again, some coaches improve players, pay attention to every single one of them and work on these things. Pirlo is still learning the craft so we have to be ready for any shit coming our way this season. I really wish he started his career somewhere else first.
As for Rabiot - he never really was worth those 7m net he takes home. I'd happily take Locatelli instead of him, that guy would love to play Rabiot's position for 2m net and most probably he would guarantee no drop in quality. Perhaps even an increase.