It’s probably a bit of both here. We didn’t have the “disposable” lifestyle 50 years ago that we have now, and a stronger push for efficiency and features has had trade-offs in complexity and reliability.
Example: My current dryer (and my dad’s new dryer) both have a lot more plastic in them. The motors are smaller, and quieter, while making the same power (or more). They are loaded with temp, humidity, weight and wobble sensors, and my dryer has 4 dials, 5 different temperatures, and 2 different modes. The old one, had a dial to control the heat, and a timer.
As for disposable, I think older generations had an expectancy that you would buy an appliance once or twice in your life. I’ve got a 1000 dollar poket shit-posting device that I’m going to get rid of because it is pushing 4 years old. We just accept that these devices are uneconomical to repair, and we toss them out. I think the only things American’s bother to fix anymore are cars, and that’s going away because every year, they get harder and more expensive to repair.