Society has evolved a lot with technology. But there were also innovations that I remember from my childhood in the 1970s -- things we don't have equivalents of -- and I wonder how many people under 25 even know they existed. That got me thinking about innovations in other eras. So I started making a list of things we don't have, ways we're more "primitive" than earlier generations. I some cases we know why they disappeared: they didn't live up to their promise. In other cases they just vanished for no apparent reason.

1970s/80s technologies

Home trash compactors. A few 1970s houses had these. In spite of its obvious practical use, I guess it was seen as an insignificant luxury. Some people had trouble carrying the heavy bags. It's a bit curious there isn't more demand now that many people have to pay extra if they fill more than a small garbage can. The environmental reaction is also different. In the 70s people were mainly concerned with how much electricity the compactors used. Nowadays we realize their electricity use is miniscule, and we're much more concerned about landfills filling up. Stull, we dump our trash uncompacted, and leave it to the garbage companies to run their commercial compactors.

Quadraphonic stereos.. Four speakers were supposed to sound better than two. It flopped because people have only two ears, and the "depth" sound sounded different to most people but not significantly better.

Silent light switches. These joined two pools of mercury to complete a circuit. I don't know if mercury toxicity had to do with their demise. At the time there were traditional switches which made a loud snap, quiet switches like what we have now, and silent switches. Silent switches were supposedly longer lasting. But most people found quiet switches "quiet enough", and if you live in a house for twenty years and only have to replace one switch during that time, aren't they reliable enough?

Intercoms. Some 1970s houses had intercoms in every room, both to communicate and to spread music throughout the house. But they broke easily: if you saw an intercom in a house it usually didn't work. A favorite use was mom in the kitchen and the kids in the basement, or for monitoring a baby. Some parents used a "poor man's intercom" of stomping on the floor, which meant "Quiet down!" Another poor man's intercom was the telephone. Telephone circuits in those days allowed the phone to serve as an intercom: you dialed your own number and hung up at the busy signal, and it would ring. Then the other extension would answer it and you could pick up the phone and talk to them. Intercoms ultimately failed as people moved into smaller houses, they'd seen too many broken intercoms, and radios appeared in every room. The musical quality of intercoms was mediocre anyway: like a cheap table radio.

Victorian technologies

Door opener. Some second-floor flats in San Francisco have a crank to open the front door, which is located on the first floor. Fortunately, even Xbox couch potatoes nowadays are athletic enough to go down the stairs and open the door themselves.

Bells. This was the equivalent of an intercom, a bell to tell the servant which room they were wanted in. Guest houses (inns) also had these. They were remote controlled although I haven't seen the exact mechanism.