It already has. You think people wouldn't have been complaining bored about the 10 chapters spent on the bomb plot in Alabasta or the 30+ chapters of fodder battles in Skypiea? My god, people were already saying OP was the worst back at the beginning of Enies Lobby and all we got were 20+ chapters of sea train fodder fights and then Luffy vs fodder in enies Lobby for another 15 chapters.
They would have called Robin's flashback boring, entirely complaining about not getting to the fights right away. A 3.5 chapter Nami vs Kalifa fight? While Zoro and Sanji get 2 only? Enies Lobby 2.5/10 for that alone /s
I've consistently found the supporting characters of post timeskip arcs to be way better than pre-timeskip. Every arc, a one or multiple Supernova have been central to the plot. The Strawhat fleet is great and has a lasting affect on the plot overall. The scabbards for example are WAY more interesting than the Franky family or Galley-La
The fights have also just been way more creative too. Gear 4 overall is a better powerup than 2 and 3. Robin's new fighting techniques, Franky and Brook's new applications to their powers. Usopp having CoO. Sanji being lightning fast. Zoro having CoC and pulling off some amazing feats. Really, everyone has been upgraded completely. The only one who I believe has gotten worse is Chopper, and this arc isn't doing him justice still at all. Usopp is kind of iffy right now, but his whole arc in DR makes up for this, something Chopper does not have.
Not only that, but post timeskip just has less chapters at this time and yet the plot has been fuller and more important to the endgame of the series. Pre-timeskip is way more about the adventure. Post has been about setting up the massive endgame to the series. Even at this rate, we still have way more to go beyond Kaido. A lot needs to be tackled and it's not even fair to compare Post-Timeskip as a whole yet, because it's set up to be way bigger than pre-timeskip and it hasn't remotely seen that payoff yet. Even without that, it's still way better.
People also can't sit here and tell me that Zou, ch 903-908, 925, and 956/957 aren't some of the greatest chapters Oda has ever put out. And it only gets better from here because all of those chapters HAVE to do with the endgame and what it building towards