I think you’ll find that multiverse interpretations of quantum mechanics, like all interpretations, are far more popular and important in the press and places like this this in science. Very very few astronomers, cosmologists and physicists are dedicating their working life to something that is broadly considered unfalsifiable.

Don’t confuse popular culture and science with the real thing. The most popular interpretation is “shut up and calculate” and will probably remain that for a very long time.