The issue is that "modern" long-running shonen especially has become it's own separate universe/bubble from the rest of anime and manga, at least in the West and as far as the audience who watches this stuff goes.
They can probably count the amount of anime they've watched to conclusion on their fingers and toes, but exclusively watch "forever shonen" that go on for years and years so in the end they're still watching hundreds, or thousands of episodes.
They think they're above "seasonal anime fans" for being mindless consumers of current things, while consuming the latest, current thing episode or chapter of whatever they're watching.
They may not believe they're "above" the classics, but they won't even go back and watch the classics ironically BECAUSE it's not the current thing, discussion of these shows is essentially over because the classics have been discussed and dissected to death.
So you essentially get millions of people who only consume current battle shonen and maybe a handful of FoTM seasonal stuff, but only if said seasonal stuff has multiple seasons.