The Marvel Cinematic Universe has brought the concept of the multiverse to new fans and has done so by exploring the many alternate worlds that these characters inhabit. As a result, fans have been able to see three Spider-Men team up in Spider-Man: No Way Home and Peggy Carter don a shield as Captain Carter in What If...? While it would be easy to consider the MCU as a pioneer of alternate realities, it was far from the first as even its best examples have nothing on the many different versions of Earth that have permeated the DC Universe.
Source：https://www.cbr.com/dc-multiverse-better-than-mcu/
