Certainly, there are fewer people who work with electronics as a hobby than there were years ago. After WWII, a lot of veterans who had been trained to operate radios took it up as a hobby. Radio Shack used to sell tubes and parts, enough to build a transmitter. As for myself, I learned about solid-state electronics when I was a teenager, then I went to college and got degrees in electrical engineering. I was shocked that not many of my classmates made electronics as a hobby. But after graduating, I learned to play electric guitar, so I started to learn how to work on the vacuum tube guitar amps that are essential to guitar players.
It turns out there is a whole subculture of people who know about electronics. Mostly, they are smart electric guitar players who taught themselves electronics, but there are a few electrical engineers who really know what they are doing. You would think that vacuum tube electronics would be a dying art but there are new people coming along who want to learn how this stuff works.
So if you think we will eventually lose all of our knowledge, maybe you can be one of the people who cares enough to make sure it isn't lost. There may not be very many people who care, but a society can function even though only a relatively small fraction of its population knows what is going on. Maybe you can be one of them.