Togashi is a true legend. I'm more impressed by Togashi than KNY. Consistency between multiple series is hard but Togashi is a true legend. Hope he takes all the time he needs to finish HxH
Here's the thing. I was rooting for MHA to hit a million per volume by Season 3. But the boost never came. S3 was (in my opinion) MHA's biggest opportunity to gain more fans. The story and fights, especially for the first half of S3, were it's absolute peak and the anime adapted these so well. But the boost never went beyond a certain amount.
It's not wrong to think MHA might be able to do more and I would have agreed if it wasn't declining in spite of a well done S4. Had it been stable, I would definitely think it needed ONE more PLUS ULTRA push to get it to that 1 million per volume mark.
However, there is no excuse for MHA's lack of growth in S4 or even lack of stabilization. It has a solid anime and people still really liked those arcs. So the fact that it declines despite a well done seasonal anime means it's definitely past it's actual peak.
Comparisons to One Piece's movie growth is not possible since OP had it's biggest and arguably the most important arc at that point in the manga with incredible reception. The attention it got from the movie came at the right time. So there was a lot of buzz around the series in general. This wouldn't have been the case had the attention from the movie come at another point in the manga.
Kingdom is another example of getting another push and succeeding but that's probably because Kingdom's original anime was pretty meh. I think Kingdom thoroughly deserves to be where it is right now, if not more. This is the bare minimum I expected Kingdom's series to have as sales and I'm happy it got that.
I think MHA lost it's opportunity to get to 1 million. It doesn't take anything away from the potential legacy of the series tho. New mangaka are already looking up to the series as their inspiration. It's legacy in WSJ and manga is set in stone.
I agree with others and think JJK and CSM deserve pushes from WSJ. JJK has every potential to be THE NEXT BIG THING in WSJ. As long as it doesn't get a Toei adaptation, it'll be fine.