IDK, I think a lot of criticism is seeping through because we are reading this on weekly+breaks basis, so the progress is way too slow and it's like watching 5 minutes of a 3hr movie over a few months.
I've started reading OP about 20 years ago, and by that time is was first 600 chapters released. I really liked it, even though sometimes it was dragging, I didn't mind. But then I started reading it week by week, and by now, I am overall less excited about it. I've changed, and the story that I loved 20 years ago doesn't have the same impact now. The story also changed (I loved Luffy more as a kind of a spiritual successor of PK and the guy with a lame DF and big ambition, I don't like the chosen one trope). But OP is still a big part of my life, and I want to see how it ends.
I still enjoy some chapters more that the others, and I re-read older arcs from time to time, but I do admit that I used to love OP a lot more than I do now. Luckily, I have a lot more other things I like, I'm writing my own novel, travelling around the world, increasing my lego collection, there's so much to do.