Would all of the Multiverses have come into creation at the same moment and wouldn’t all Ricks and Morties be the same age?
As Rick and Marty jump from universe to universe wouldn’t time go on moving forward at the same pace in all universes? So the time rick spent fighting with bird man and hunting down other Ricks, wouldn’t the lives of the other members of his family in other universes have lived their life and be older by the time Rick got back.
For example, Pre-portal rick was approached by a Rick that had portal tech and then presumably bombed Beth and Diane which motivated Rick-137 to develope the portal gun.
My best explanation is that cartoons don’t age like on The Simpsons so in effect cartoons live indefinitely and time is not moving forward when it comes to the story unless its a flashback to when they were younger.