It’s easy — really, too easy at this point — to proclaim that the era of superhero movie is over. As the start of this month, Marvel’s “Thunderbolts*” opened to some of the strongest reviews the Marvel Cinematic Universe has received in years, and yet, by the end of May, it will have earned less domestically ($174 million to date) than 2022’s “Doctor Strange in the Multiverse of Madness” did in its opening weekend ($187 million). Last week, Marvel Studios announced that it was pushing “Avengers: Doomsday” and “Avengers: Secret Wars” from May to December of 2026 and 2027, respectively, while pulling three other untitled Marvel projects set to open within that same timeframe from the schedule entirely. The former decision will allow directors Joe and Anthony Russo more time to marshal two of the biggest, most expensive feature films ever made. The latter decision is pure commerce, an easing of supply in response...