> Besides the Internet and maybe smartphones, what new classes of device were created post-1970s that had a major technological, sociological, or medical effect on society?

Neodymium magnets and incredible power density motors they enable. Lithium ion batteries with carbonaceous anode.

As a result drones and other things.

Blue led, OLED. Insane pixel density screen manufacturing Technics.

GPUs

I'm not sure how you can get such blind spot that you don't see immense scientific progress that was made since the 1980s

Literally a better part of a day of average Westerner is spent by looking at things that weren't invented before 1980.