Don’t get me wrong. I think the manga itself is good, and I think a boost would have happened regardless, but the anime definitely took the boost to the caliber that it did. Especially all the hype and buzz around episode 19 of the anime.
Sure, sometimes you get cases like Tokyo Ghoul, where the anime isn’t that good, but a huge boost still happens. But cases very from anime to anime, and adaptation to adaptation. And how people are exposed to the anime.
I think it shouldn’t be underestimated how good of an adaptation Kimetsu was. MHA as a great adaptation for the most part, but Kimetsu’s adaptation blows it out out the park in terms of consistent sakuga animation like every episode, soundtrack, cinematography, atmosphere, and the series just has a plain cinematic look to it. It probably has one of, if not the, best Jump adaptations ever in terms of pure production quality. Idk if Black Clover would have exploded to the levels of Kimetsu(probably not), but if it had an adaptation at even half the quality of Kimetsu I’m sure it would have saw a way bigger boost than what we’re seeing now.