I have fatigue reading about comic book movie fatigue.
But seriously, it's a genre that will ebb and flow. I think they will continue to make them, but they will, at some point, not dominate as they do now.
Think Westerns or Spy movies or Monster movies or Slasher films...SciFi was big in the 50s, but fell to few and far between before Star Wars revived the interest. Now some genres fade to almost nil, like sand and sandal epics, but I feel they will continue to make them as long as they make money. Too many failures would make studios shy away. So The Gunn DCverse and next phase Marvel will be big factors.