That's what I thought when I was waiting weekly during the Dressrosa Arc. A lot of random things were happening in the beginning and it was so dragged out and it became too boring to me. I decided to just drop One Piece........ only to return 10 years later to read tons of chapters again. Now I just read the manga every few months or years and not weekly, so I don't 'think' it drops in story quality.
At this point, your options are to wait for a few years to pile chapters then read it... or just drop it entirely if you don't think it's worth it -- since without actual data, what you 'think' the quality is is mostly subjective and may be influenced by the slow weekly updates.
With due respect, this is only my opinion and not all may agree to it and I understand your side even though I might not relate to it being a monthly (sometimes yearly) reader.
Personally I like this style. It lets me place where exactly this happened in the timeline and makes the world feel dynamic. Outside of Luffy's adventure, everyone was being the main character of their own story. Everyone doesn't revolve around Luffy. The world feels alive.
i feel like the quality of the actual storyline is decreasing. I don't see much people talk about the present compared to how much people get hyped with the flashbacks.
I know we're currently in one, but I notice it even out of it too.
People used to be like "OMGG this plot twist just happended" now it's always something like "X years ago, Y was with Y doing Z"
I dropped it at the Vegapunk arc because the present was boring to me and the reasons people gave me to continue are the flashbacks