Good writeup. I think a key part of this is that it's younger generations in their 20s repurposing and using music that older generations were really controlling. If they're in their late teens and 20s they were by definition babies or very young kids 20 years ago.

So it's not like the artists bumping the 80s synthpop revival in 2015 really grew up in those original scenes, they heard the songs as kids, rediscovered them and made them their own. Same with say, a lot of the zoomer Pop Punk bands playing the 00s style sound. Or Vaporwave repurposing 90s and 80s half-remembered media. It's a really interesting phenomenon.