There is no such thing as "Superhero Movie Fatigue."
Just like there's no such thing as Rom-Com Fatigue, Murder-Mystery Fatigue, Horror Fatigue, Thriller Fatigue, Sci-Fi Fatigue, or Action-Adventure Fatigue.
What you (and I) are sick of are movie studios throwing exorbitant amounts of money at iconic characters with no research, dedication, care, or interest in figuring out why they're so relatable to so many people and asking you to fill their pockets with money since they spent so much money on them not realizing that their product is terrible.
Marvel Studios is not one of those companies.
Marvel Studios does not have a "Catwoman."
Marvel Studios does not have an "Spider-Man."
Marvel Studios does not have a "Wolverine: Origins."
Marvel Studios does not have a "Batman V. Superman."
What Marvel has done is take 22 films over the past decade to tell ONE coherent story. Yes, there are off-shoots that try not to touch the main throughline before their time, but they are still part of the same story. Star Wars will have done 11 films by 2019. Harry Potter will have done 10 by next year. James Bond has done 24 films over 50 years and they barely stick to anything of coherency.
What Marvel is doing is unprecedented. That does not mean it's immune to criticism. They have (well, used to) a villain problem. They have (or often) undercut dramatic tension to sell a joke. There are (sometimes) resets of character progression keeping heroes the same at the end of their film as they were in the beginning.
However, all that criticism is low compared to the heart, honesty, and belief in who these characters were on the page in the first place. A belief that these characters are fine and heroic AS THEY ARE and not treated with a silly stick or a need to change ethics/morality to be more modern. It took Producers, Actors, Directors, Screenwriters, Costume Designers, CGI Artists, Composers, Light Crews, Sound Crews, Location Scouts, Production Assistants, Stunt Crews, and many, many Extras of many different backgrounds, races, genders, and religious upbringing to make all this happen.
If you don't want to see Infinity War, then that's fine. You don't have to see it. If that trailer yesterday made you want to see it, but you're wary because you didn't watch the others, then you definitely have time to join all the crazy discussions of it. I say you watch from the beginning. I don't want you lost. You wouldn't watch a series finale without watching the series, right? Yet, I'm a completionist so I can definitely understand not agreeing with me. But, for those who scoff, look down upon, or disregard these movies and their fans outright for not being a kitchen sink drama and lug them with the studios of Fox, Sony or Warner Bros: Get an imagination and Take A Seat!
I say that as kindly as possible because I find your lack of faith in the in the belief and inspiration of modern morality tales that stretch across all human lines for children and adults alike...disturbing.