What is your theory for why 80s cultural artifacts have become mainstream again? 

E.g. music like ABBA, Everyone wants to rule the world, etc; entertainment like Stranger Things, Breakfast Club; fashion like the shades, etc 

Working theory: internet native youths subconsciously yearn for an analog world

1) 20 years fashion cycle owing to a previous generation getting older = getting in power, and demanding+refining what they consider the best, which is what was in vogue when they were teenagers. 2) Yearning for safer/better years, similar to (1)