We need to accept a few things:
Busquets:
-- good in taking the ball out from our box into the opponent's half. When he is not there, we often suck in that area.
On the other hand, against counters and big teams, he is lately horrible in defending due to his pace
Rakitic:
-- not that good in getting the ball out from our box to an opponent's half
-- but he covers way more ground and imo defends better than Busi (don't look only at tackles in stats). Raki makes a team "cohesive"
In the near future, I would rather bench Busi that Rakitic.
Rakitic could be a Cdm, helped by Arthur, who could get the ball out of our half.
Or, Arthur could be a Cdm, helped with Rakitic as a Cm.
When people say that we can't replace Busi, that is only in a part with getting the ball from our box into an opponent's box under a pressure.
That could be solved either by Arthur, by counters, fullbacks, wingers who can run etc.
But, if you want a slow TikiTaka buildup with 100 passes from our box to the opponent's box, then Busi is irreplaceable.
I think that when Busi will be gone, it will be exactly the same as with Iniesta in the last 2-3 years:
A team will be equally as good/bad with or without them.
Raki has his pros and cons.
Busi has his pros and cons.
Arthur has his pros and cons.
The only thing that is sure, those 3 are all too slow to play together against big boys.
What elite midfields did Rakitic come up against in the WC? In the UCL he always comes up missing when the team needs the midfield to assert itself on the game.
You mean, Rakitic goes missing surrounded with turtleslow-pasthisprime Iniesta, Busi, Luis, Messi and similar?
Raki goes missing the same as the hole team against any bigger team.
He wasn't any worse than the best player in the world, more or less.
Raki went MIA is less matches than Messi.