If Captain Marvel could save the world, why did Nick Fury wait until he was half-snapped himself to contact her? Well, Marvel Comics' Captain Marvel Prelude #1 just came out to connect some dots. Will Corona Pilgrim explained what Fury was thinking in that final Avengers: Infinity War scene:
Captain Marvel will make her debut in her own film this March, followed by Avengers 4 in May. Captain Marvel Prelude #1 paves the way by giving more context to the Infinity War ending, and also ties in Avengers: Age of Ultron and Captain America: Civil War.
In the new comic (via Polygon), Nick Fury and Agent Maria Hill reference Captain Marvel in a conversation set after Captain America: Civil War. He says the infighting rift between Tony Stark and Steve Rogers over the Sokovia Accords is something they can't afford. But he still believes the Avengers would come together in a major threat to humanity (like Thanos).
Maria Hill references never meeting your heroes because they'll disappoint you. Fury quips, "Not all of them." Maria asks if he knows one they haven't called yet, since it might be helpful to have a back-up plan. Fury replies "Nah. If we do our job right, we'll never be in a position of having to call HER."
Well, whoops, 'cause he did have to call Carol Danvers/Captain Marvel. The new comic goes into greater detail, but at least we have an official Marvel explanation for why Captain Marvel was the last resort instead of the first call. It also seems to be the explanation for why they haven't called Carol Danvers every time the Avengers have faced major threats. We know more backstory is ahead in Captain Marvel, which is set in the 1990s, and more tie-in answers will follow that in Avengers 4.
In terms of what makes Captain Marvel so much more special than Earth's Mightiest Heroes, Marvel Studios President Kevin Feige previously explained that she's more powerful than any character the MCU has introduced thus far.
But then what? Presumably Captain Marvel is going to stick around, as opposed to Brie Larson's heroine just exiting stage left after a big round of thank-yous from that other half of the planet.
After the first Captain Marvel trailer, we still have more questions than answers, but the full story is coming March 8, 2019. Not quite two months later, the MCU will give us more answers -- and mark the end of an era -- when Avengers 4 is released on May 3, 2019. After that, we already know Nick Fury will be part of Tom Holland's Spider-Man: Far From Home in July. Boomark our 2019 movie release schedule for updates on everything coming out next year.