For a while there, Marvel couldn't stop ruining its own movies. In pre-release trailers or marketing, the famously watertight and spoiler-averse Marvel Studios sprang its own leaks.
Whether it's Captain America: Brave New World's third-act Red Hulk tussle or Doctor Strange in the Multiverse of Madness revealing its Captain Carter-led alternate-universe lineup ahead of time, it's perhaps my most frustrating issue with how the modern-day MCU handles its output.