I love Raiku Makoto's mangas with all I have. And I've re-read Gash a lot of time. In my own world, it is undoubtedly one of the best, the finest that would ever be.
However, to compete and win against One Piece... I think it's a reach. Gash was immensely popular, but not everywhere it went. One Piece, on the other hand, has reached the level of Dragon Ball Z's stardom. It's hard to compete with either, even if you're Sailormoon
It really is up to the readers, how they react to the work and if they welcome it so, to which level.
That reminded me of Animal Land. Such a good manga! I feel like it was even more complicated than Gash. But no matter how good it was, it never surpassed Gash or became as prominent.
I agree, Raiku Makoto has had it tough with the publishers. I'm still glad he went independent and has been able to do things on his own and achieve certain successes with it. Sensei knows for sure, there are fans like us, always eager for his next things.
Keep in mind that ZB had to change magazine twice mid run, went on hiatus, and had an incomplete anime, and yet still managed to keep up
Anything similar happens to any other series and they just die
By comparison OP has had the full support of WSJ for almost 3 decades, and even then it is just in these last few years with Film Red and the live action adaptation that it is starting to get the proper international attention that it should have 20 years ago, and that's in the middle of Wano which is a mix bag if an arc, thanks goodness Egghead is going pretty much perfectly
OP itself has yet to reach the peak of its popularity, still trailing behind DB when it comes to the world at large, something that the anime remake could fix, on some places even trailing behind Naruto, for the manga plus international ratings Boruto and JJK at times even out performing it (neither series being anywhere close in quality, they just come with better anime)
That's a 20 year setback just by having a bad dub for its early arcs, and a current anine adaptation with a weekly model that is no longer trending, while everything else goes more than perfect
If ZB had things go that well I am sure Raiku could have done it, 30 years of uninterrupted serialization for an author this good who can keep up this quality is rare, only Oda and Raiku can pull this off, in fact it took Toriyama himself (RIP) quite a bit to get back into the groove, and that's with him just doing the writing side of things
Everyone else peaked back in the day, Takei is on some marvel bullshit with Shaman King Flowers being divided in a bunch of spin offs with a story that refuses to advance on a conflict that doesn't feels justified, Watsuki is shamelessly milking kenshin for something that has no merit to exist when we already know that the batusai dies of tuberculosis after being a deadbeat father, Kishimoto peaked on the Pain arc and it doesn't seems like Boruto will change that any time soon, Togashi is pretty much retired, and Araki pivoted into doing seinen manga, Kubo couldn't even do his own manga right drawing it more as a storyboard than a manga, and is relying on adaptations to keep up
Everyone else has yet to go through the gantlet
But Oda and Raiku not only keep going they still keep getting better at it, I have no doubt that all things equal Raiku could have done it