I disagree.
We've had some subplots that didn't feel that necessary (Urashima and Holdem) and others that, albeit relevant, were dragged more than they should or were developed in a poor way. I'm thinking of Udon, which not only lasted longer that I could enjoy but felt like a teen camp instead of a prison by a crew of beasts. Sometimes it got ridiculous and unbelivable, like the threat of maiming Luffy because of his behavior towards the jail officers (implying Kaido would risk a 1.5b warrior for the sake of a SMILE nobody). At the end of the day it was so childish that lost my interest, and things like dragging Kawamatsu's introduction only for it to be so lame didn't help either.
Also, Oden's flashback is a bit of cheating since what makes it most interesting isn't Oden himself but the things surrounding him. This isn't that positive because this isn't Roger's or Whitebeard's flashback but Oden, and the flashback itself isn't perfect either (mainly having some big problem with depicting Shanks and Buggy's ages right). I personally don't like Oden and, while I'm enjoying the glimpses of information about Whitebeard, Roger and co., I'm still waiting for some actual trace of genius writing in this flashback (such as the tragedy of the mushroom in Chopper's, the death of the Rumbar Pirates and how it is built on music, the small details in Doflamingo's or the amazing resolve of Big Mom's).
On the other hand, the events seem developed irregularly and sometimes they are random (even Sanji stressed how they somehow met Kin'emon with no deeper explanation) or omit interesting conversations (Luffy telling his crew that Big Mom is in Wano was ignored in spite of its importance). Yet, Oda recreates with characters he shouldn't care that much about.
By the way, and even though it isn't pacing-related, I'm not a fan of Wano's designs, too much Japanese stuff but not so much smart and creative manipulation of such material. The most innovative are some SMILE users, but they're one trick ponies (funny but not meritorious). Coming from Dressrosa and Whole Cake, Wano is underwhelming and overall lacking.