Comic books are a niche hobby. Comic book movies are far more popular.
Meanwhile, in Japan, manga are very popular and manga series are often even more popular than the anime that are made out of them.
Two different markets.
Comic book sales have sharply declined since the 90s but have been steady over the last few years.
However, the infestation of Social Justice parasites in Marvel is literally killing the industry and driving independent comic stores out of business. Distribution agreements mean that for every X-Men or Spiderman, retailers are forced to stock issues of Squirrel Girl or America Chavez that are virtually impossible to sell.
Also, the movie franchises that should be boosting comic sales bear no relation to their print counterpart. A new fan inspired by Robert Downey Jr's on-screen Iron Man walks into a store and leaves disappointed after finding out that Iron Man is now a (completely insufferable) 15 year old black girl...and Thor is a woman...and Hulk is Korean...and Captain America is literally a Nazi etc.