Old technical writing is the same. Check out this camera repair manual from the 80s: https://www.dropbox.com/s/36tlkpnrsbmszar/nikon_fe-fe2.pdf?d...

Clear, easy to understand. A patient person without any prior knowledge of cameras or tools could follow the instructions in here and completely disassemble and reassemble the camera as well as troubleshooting any problems with it.

I think the reason is A) there was no internet! These books and TV shows were as good as it got. No googling if you have any questions.

B) They had to appeal to a lot of people. Now the audience is bigger and everything is more niche. General TV has deteriorated to news entertainment, sports, and reality shows, because that is all anyone who watches TV now is interested in.

I was shocked at how good this segment from the "glory days" of TV was: https://youtu.be/eDw5Y8qSmBk

It's interesting and well researched. They spent plenty of money doing locations etc. Network TV just isn't this good anymore.