We can say the same for every genre, there are more dumb silly romantic comedies that make more money than the Woody Allen serious romantic movies.
the issue here with the genre of superhero films is that because of how powerful Disney is, the media that for some weird reasons plays favourite with some franchise and the attraction/illusion of the its all connected movies formula, all these has led to silly movies dominating the more serious movies.
I have no doubt that this is why all these directors started having a bad thing for marvel because they see it as silly and some cannot understand why they get so much hype, although I am sure they know disney are their parents that can give them the world. However Marvel's overall movie reputation in mainstream should never have shifted from the balanced style of what Singer and Raimi did in the early 2000s.
I think for Marvel, their serious movies should matter more and they do.