I don't know about one piece, but naruto is huge too, but mostly due to filler eps. You can skip like half of it just by googling up for fillers.
I started One piece a while ago though I fell behind recently. I get that it's really long and that might put you off tho tbh I noticed that recently especially with the One piece episodes they spend a lot of time on the recap in the beginning so I just skip through that if I'm binging a few episodes. I'm like around episode 774 ;-; so I still have a few hundred to go too