So I hear The Flash bombed hard. And I've heard superhero films in generally have been on decline, probably since the MCU Thanos arc wrapped up in 2019 and it lost the most popular actors (including Boseman), oh and plus Covid. Plus, the general aimlessness and over-saturation of MCU and the continued unevenness of DCEU, and the weird splintering of alternate versions (Joker, the Batman movie with the Twilight guy, etc).
It's a DC Superhero movie not about Batman, with a star that has allegations about grooming minors of course is going to bomb. It managed $267 mil worldwide. Blue Beetle did even worse $121.5 million worldwide. I don't know exactly why but DC superhero movies don't tend to get the same audience as Marvel movies (the fact they are dark and depressing a lot of the time can't help).
Marvel's recent releases are of course going to struggle to live up to Endgame, but Guardians 3 Marvel's last movie grossed $845 million, compared with 2 that grossed $863 million, there first outing was $771 million. Black Panther 2 (2022) grossed $859.2 mil.
The Eternals that was generally poorly received about a group of heroes most people have never heard of still did $402 mil, Shang-Chi another pretty unknown hero $432 mil. So both nearly twice the box office of The Flash. Ant-Man Quantumania was terrible and still did $476 mil, but Ant-Man really isn't a big name in superheroes.
Still look at the Spiderman movies since Endgame, Far from Home, $1.1 BILLION worldwide, No way home $1.9 Billion.
Then the Spiderverse movies which considering the art style could be considered a real gamble, the first one made $384 mil worldwide, but the second made $690 million once people knew how good the first one was, hardly loosing steam there.
Wonder Woman (2017), went from $822 million, compared to WW 1984 (2020) did $169 million a massive drop but to be expected with COVID still a big thing at the time.
Captain Marvel grossed $1.1 billion worldwide, be really interesting to see how well The Marvels does. If it is less than the $400 million of second string Marvel movies then yeah it isn't looking that good for Marvel outside their main characters.
I think Marvel have sensibly reduced the number of movies they release in 2021 they had 5 movies out, they are back to three a year now.