Without looking at statistics, no.
If a very good Superman, X-Men, avengers, and some other new thing I never heard of all came out in the same year, there is no reason why they can’t all do well.
Keywords there being “very good.“
It has nothing to do with their genre.
Now, if one were released every two weeks, some people will have to make choices. That’s not fatigue. That’s economics of finance as well as time.
If the films are not very good, that’s not indicative of fatigue. It’s indicative of movies with poor word of mouth.
If the films are politically attacked, that’s not fatigue, either.
If fatigue exists, I believe it has more to do with repeating the same formula. It’s a lack of creativity. When you can guess what the next line is going to be in the film, and be correct more than 50% of the time, sure that could lead to fatigue. If you know how it’s going to end when it starts, if there are no surprises, if the bad guy is a bad guy because his mommy didn’t hug him enough yet again: all those things can lead to fatigue. It still has nothing to do with the genre itself. It has to do with the formula.