I dont think that's quite fair in terms of the semi-RB role.
You have to remember that Pep "isn't one for the tackles". When Rico plays there he isn't expected to output goals and assists or even penetrating passes - he's really just to link the defence to the more creative players. Often if he's getting caught in possession, it's because there aren't options available - with Pep's tactics there should always be players available for passes, so if that isn't happening it's not down to the player on the ball.
When people are shouting out for players who are better defensively, well that would be the ideal - as long as they could look after the ball as well as he does also. Those two skillsets don't always go together and Pep will always prefer players who are good on the ball.
It's a bit like the problems he had in the first season here - people telling him to water down his tactics and go a bit more safety first, but instead he dialled it up to 11.
With respect, I disagree with this.
The ideal semi-RB role is someone who both defends well, and passes well. The role isn't solely about the ability to "link the defense" - it's much, much more. And it's such a complex role that few players can fill it to perfection. Why? Because not only does this role require excellent passing skills and - since you're the RB - excellent defensive skills - it also requires the ability to read the game - knowing when to move forward into a midfield role - and when to retreat into a defensive RB role. And it requires pace - because you'll often be far forward - out of defensive position - with the immediate need to rush back towards your own goal to fill defensive gaps.
Rico is manifestly unfit for the semi-RB role on numerous counts: he's not good on defense; he's not good on offense; he's slow; he doesn't read the game well; and when pressed on offense - he gives the ball away too frequently.
===
I think we agree that Rico is unfit for the semi-RB role.
Let's move on to a midfield role
====
Rico is not suited for a midfield role either.
The midfield role in Pep's system is this: keep the ball, move the ball quickly, see the game - pick out the excellent pass to defeat the defense if available; always, always, always, move into a triangle with other teammates - the triangle formation ensures that the maximum number of players are available for a pass. And, when the ball turns over, immediately press - either the ball - if close to you - or cut off passing lanes.
Rico doesn't do most of this.
Rico doesn't make penetrative passes.
Rico doesn't move from three-in-a-line to form passing triangles often enough.
When the ball turns over, Rico doesn't participate adequately in the ensuing press. He's slow and can be dribbled against. He can't read the game: meaning that Rico's ability to, at the very least, cut off passing lanes, is poor. In short, when the ball turns over, Rico does little to make sure we rapidly regain the ball.
Finally, Rico isn't good at all when pressed. When we have the ball, against a team that's going to press us, Rico is a weak link. Rico either can't find an open man (usually because he doesn't have a mental picture of the field when he receives the ball) or draw a foul (he's not strong on the ball and can be bullied) or pass back (mental picture of the field is poor) or hoof it out-of-bounds as a last resort - with any consistency. He'll give the ball away much more often than any of our other players in a midfield role.
===
Which leads me once more to summarize Rico:
Rico is an OK-ish backup midfielder against teams that mostly won't press (in this regard, Forrest is the perfect opponent against which to play Rico). But is this an adequate baseline performance bar- even for a backup - for a side that expects to challenge for the Premier League and Champions League titles?
No, it absolutely is not.