Probably will run another 10 years...it's an epic.
There's a LOT of shyt that Luffy needs to before the series ends that he hasn't yet. Has to fight the Yonkou (Big Mom, Kaido), has to fight Blackbeard (along with his crew), has to fight Akainu, has to meet his dad, has to hit up Wano, has to hit up Elbaf, has to discover the true history of the world and what happened in the blank century, we still haven't found out who the unknown Warlord is, still hasn't met up with some of the other Supernova like Kidd and Hawkins, Zoro still has to fight Mihawk, Dr. Vegapunk still hasn't appeared yet, there's still an Admiral we haven't seen yet, Luffy still has to have his rematch with Smoker, we still don't even know what the "D" in Luffy's name stands for yet, we don't know Kuma's full backstory yet, we still don't know the truth about Devil Fruits, we don't know about the Ancient Kingdom yet, etc.
And that's not even mentioning the world war Whitebeard foreshadowed and finally finding out what One Piece actually is.
Could EASILY go on for another 10 years if Oda wants it to.