>>527184248
one piece was always popular it's just that it sorta isolated itself to become even more so because stuff like naruto and bleach died on top of toriyama dying
plus i would say it gained appeal to people who like anime because the series is so long which means it has a lot of content to go through and you kinda know it's still ongoing rather than being abandoned or the mangaka dying.
it's like why people who want to game end up playing the same stuff that has been up for a long time with an extensive history which atleast means the service/series will be ongoing reliably for a good while rather than abandoned or flopping on it's first week of release and so on.
god knows how one piece manages to still keep their animated series going though, last time i checked it was awful, i know a lot of people hated the mangas drawing too.