That?s sorta what Ajax did under Ten Hag. When they bullied Benfica, Bayern, Juve and Madrid they let Frenkie rampage from deep down. Sch?ne, Mazraoui or Blind would hold the fortress. This allowed them to always have a playable option up front, because Frenkie dribbling into the lines between the opponents midfield and defense created this. He became to be known as the player who couldn?t be pressed and never played the ball back or sideways, always forward (he had a pass accuracy above 90% doing this aswell, even against CL elites).
Barca just don?t want to tactically change their way of play or sub of Busi. So they play him CM and hoped FdJ would develop as a more attacking midfielder, because he does have elite ball retention. Turns out, FdJ had way too little attacking qualities for the CM/AM roll. He lacks shooting abilities and an attacking instinct (not so weird when you figure out he played DM and CB all his life). In this role, he became mr. Ping Pong.
I still belief Frenkie is world class in the deeper playmaker / defensive midfielder roll. He still shows this at the Dutch NT often. Even at Barca, he linked nicely with Dembele and Messi in his earlier years in a deeper playmaker roll. Made him player of the season, even.
I also believe that Barca with Xavi would just rather stick with playing Busi and buy the La Liga win with just signing other players. So one way or the other, he must leave.