What is something that's crazier than the wildest dreams of any ~1970s nerd, but exists today? I'll start with an easy one:

Personally, I’d go with 80s/90s nerds, as it would take a special kind of 70s nerd to understand digital storage enough to be wowed by a 4tb sd card.

Multi-gigabit network speeds being common in people’s homes. 400mbps+ wifi speeds being common too.

4KUHD tvs and on your phone. Small B&W crt tvs were extremely common.

Bluetooth headphones, cords were a pain.

The more I say, the more I think, basically everything.