The MCU has recently delved into the world of What If? which is a title Marvel Comics has been creating stories under since the late ‘70s. While the What If? banner is still going strong to this day (both in comics and the MCU), it’s fair to say that the ‘80s and ‘90s were when they were the most prevalent in the comic book community. Not because those stories were any better or more impactful than the ones told before or after, but because that’s when a great number of fans were not only more knowledgeable about these characters, but also the most passionate about them as well.

https://screenrant.com/10-90s-marvel-what-if-mcu-needs-adapt/