Go a few pages back, the arguments he pulls to say that JJK's writing is good, are laughably pathetic, that and Mutsu trying to defend Yuji's sudden powerups.
I plan to do so later on but give me a second on that one.
Imagine trying to say that Gon and Ichigo are absent protagonists when a large part of the story is about them growing and developing. On the other hand, Yuji literally only has one important fight in the Culling Games arc and then disappears for 90 CHAPTERS. And his character never changes past Shibuya.
I know he's saying this in regards to Ichigo's absence in the final arc during the 2nd Invasion but it was actually confirmed Kubo DID want to have some focus on Ichigo during that final arc in the manga but it didn't pan out(He didn't want to break the pacing he made) which is why in the anime, we constantly got what Ichigo was doing in the Royal Palace in every episode.
Itadori barely matters in his own story until only now.