Why are people still discussing this?
Oda has been sick multiple times due to his lack of sport and overall daily/weekly working schedule. Because of his health his got set breaks every 3-4 chapters. He also have to walk 30min a day outside I heard?
Additionally to that, there are WSJ breaks for holidays, and those aren't counted into his own breaks but separately.
Furthermore this year there have been additional breaks because of Covid-19 and the safety of Oda and his assistants.
If you compare it to other artists, doesn't matter if manga/webcomic. Barely anyone is drawing any amount of panels alone. Oda has his assistants, and webcomic artists are just the same. They got assistants doing the lineart, the coloring, the effects.
Not even going to mention the difference between traditional art (Oda) and digital art (most of webcomics, and even magakas nowadays, I think also Horikoshi with MHA). Digital art has a lot of pros in terms of sketching, lineart, coloring, etc etc. It is way faster. Traditional art with ink is difficult. If you fuck up a few lines, you can basically start from anew. The sketch, the lineart, etc. Do everything again from the start. The paper can rip from erasing. What if you spill ink? Fucked up the screen tones? There's so much to take into account.
You can dislike all the reasons I have counted but these are solid reasons. Not to mention, everyone got their own pace while working. Some are faster than others. I also got to add as last point that he isn't just drawinf 24/7. Working with his editors is essential, talking about the manuscripts, the storyboards, plans, and then just drawing the whole thing. It's a solid rhythm of working steps and they take a lot of time. Believe me.
I won't ever argue against Odas pacing because I am a (comic) creator myself and I know how much work it is to do everything alone and even with help. It's not that simple.