OP is getting more sales due to FOMO and timing, if Naruto and Bleach were still a thing I think OP wouldn't get as much attention as it's getting now, it's like the only golden goose shitting bad turd and inside that turd there is gold
Yeah Naruto was a bit more popular in the west thanks to the anime and Ninja's being more popular than Pirates especially during the early to mid 2000s but when it comes to Manga sales op was always consistently on top
And taking into account the length of one piece and how toxic the fan base can be these days new fans are a dime a dozen
