The fact that Marvel movies like The Avengers and Captain America are coming out in the 2010s instead of the 1990s is mostly just a matter of studios dragging their feet and licenses changing hands.
Many of these movies were proposed and approved in the late 80s, and by the 90s development had begun, which eventually stuttered to a standstill until the 21st century.
Some of us have been wondering which actors would have been cast in the Marvel movies since they were first proposed, so Redditor thamonsta came up with a great idea- decade specific recasts for Captain America: Civil War.
He even took the premise a step further and came up with casts for the 50s (which is off since a few of the included actors weren't famous until the 60s) all the way through the 90s.
My personal fave is the cast from the 1970s- John Ritter as Ant Man and Burt Reynolds as Iron Man- sounds like a cult classic in the making!