the assumption is, that Marvel is getting more than its share; that Marvel is 'taking away' from other movies;
and if Marvel simply didn't exist, then OTHER movies would be hauling in that exact same amount of revenue.
(somewhere around $32billion, total)
https://www.the-numbers.com/movies/production-company/Marvel-Studios
the reality is, Marvel generated $32billion for an industry which would NOT have been generated otherwise.
and it created a whole new generation of movie-fans who actually LIKE going to theaters again.
(read: the kids who grew up on Marvel Movies for the last decade, will create a ripple-effect,
which will see these fans growing up and taking their OWN kids to the theater, in the COMING decades.
without this "superhero fad" then the very Ritual of "going to the movies" might have died off completely,
as the new generation of millennials would be perfectly content to watch movies on Netflix).
Marvel was a HUGE shot-in-the-arm for the ENTIRE industry. the "superhero fad" helped everyone.
there are more people working in hollywood now, (and more 'butts-in-seats'), than any other time in history.
this could NOT have been accomplished by 'Rom Coms' (nor 'Ridley Scott' films -- he's just spouting sour grapes).