Technology 40 years ago was so simple, that anyone with basic education in electronics could understand how this or other basic utilities work and when opened up could identify which component does what and if you identified a faulty component you could often easily replace it and thus repair it on your own, and skilled individuals could probably make their own from scratch if they could source all components and didn't care about patents....
Nowadays even the products which didn't evolve much since then are often made very hard to repair + new technologies are increasingly more difficult to understand and state of the art technology in some areas is so complicated that we're literally dependent on one or two companies who can make it for us (3nm chips for example, or web browsers in software)..
It will be very interesting to follow how much the complexity will increase in the next 40 years..
Nowadays even the products which didn't evolve much since then are often made very hard to repair + new technologies are increasingly more difficult to understand and state of the art technology in some areas is so complicated that we're literally dependent on one or two companies who can make it for us (3nm chips for example, or web browsers in software)..
It will be very interesting to follow how much the complexity will increase in the next 40 years..