There’s one thing that Marvel used to do better than any other studio, and that’s build hype. Ever since the series debuted with Jon Favreau’s “Iron Man” in 2008, these superhero films were filled with promising easter eggs and, in a game-changing creative masterstroke, post-credits scenes that promised future characters and crossovers and villains, which Marvel then actually delivered.

Now, Marvel has made its worst MCU post-credits scene ever with the tag for “Captain America: Brave New World.”

Marvel didn’t invent the post-credits scene — so-called because they drop after the closing credits (sometimes spiked with a mid-credits scene as well or instead) — nor did they make the first good one. The first, according to most historians, came at the end of the 1966 spy comedy “The Silencers,” starring Rat Pack crooner Dean Martin as Matt Helm. The scene depicted Helm on a bed, either pre-or-post-orgy, with a cadre of scantily clad,...