People keep pointing to him being "dropped" for the Champions League Final, which isn't what happened. We played a different system without a holding midfielder so we could get an extra forward in the team. Now the narrative is that Pep didn't fancy Rodri (or Fernandinho), rather than Pep changed our shape entirely.
The people that use this narrative never liked Rodri to begin with. That's why they never point out (until yesterday at least) that Fernandinho also didn't play in the CL final. It's just ammunition to them.
I do sense that a lot of people really want a player who covers every blade of grass putting tackles in, but that is just fundamentally at odds with how Pep sets his teams up. Defending is everyone's responsibility, not just the one nominal "defensive midfielder." Whenever we've looked defensively solid under Pep, it's because our press has been great, we've dominated possession, and we've executed properly in both penalty areas.
Rodri is one of those players that is really fucking boring to most fans. We have a few of those in this team. Bernardo, Jesus, Zinchenko (although the tide is turning bit by bit), Gundogan for a long time, Walker for a long time, even Sterling at times too. They aren't players that do too much direct stuff. They don't charge into tackles, they don't shoot and score too often, they don't create much that often. It's just all understated.
You have to be a bit of a football nerd to get it, and unfortunately it's very boring and lame to be a football nerd.
And people genuinely don't seem to understand what it is each of these players are supposed to be doing (after all this time, still). Good or bad, the players in question are doing as they're told and they're doing it well enough to keep getting picked.
That's all because it's a team game. Everyone does their little bit. That's why when it works, we press amazingly well. We pass amazingly well. We defend amazingly well. And as long as we don't have a terrible day in the boxes (as Pep would call it), we get amazing results too.
If we signed Bissouma, same rules apply. If he does his part for the team and they do it for him then great. But if not, it really doesn't matter who's playing in the position.