The Marvels doesn't deserve this fate. I thought it was an enjoyable film, but not a must-see film. It was more run-of-the-mill. Sometimes the internet or mass audience turns on a film and people seem to enjoy bashing it. This summer it was The Flash, and before that, arguably Shazam! Fury of the Gods, and last year it was Morbius and Black Adam. Marvel has generally avoided getting this kind of treatment, though The Eternals was met with a big yawn, Love & Thunder caused ripples of disquiet, and Quantumania was ragged on, so there has been a growing displeasure with superhero films and content. I'm iffy about superhero fatigue setting in. I still think it's more of an issue of quantity over quality. Across the Spider-Verse and Guardians of the Galaxy Volume 3 both did well this year, and Teenage Mutant Ninja Turtles made respectable box office.
I think Disney might be getting the message that less is more. Unfortunately, they got to contend with Sony who are putting out Madame Web, Venom 3, and Kraven all next year I believe. And even though they aren't MCU films, they still have the Marvel logo, and could tarnish the brand more if they flop. Disney needs to find a way to build back up mass audience trust in the brand. If they can't, they should start making cheaper films and Plus content for the more dedicated MCU fan base that's still out there.