The golden age people are trying to recapture is the aftermath of a world war that decimated almost every major power except the US and then the US happily rebuilt everyone’s economies in exchange for riches and power. The 21st century looks very different and only really MAGA folks are looking to rewind the clock as a way to move forward.

The economic theory of MAGA, is that the united states yes rebuilt the world but also exported the US consumer economy through asymmetric nonreciprocal tariffs. Rebuilding countries made money by selling to the US consumer, not the other way around.

You can argue that it's overall bad for the economy, but I think you're missing the arguement.