As a general rule old tech is far more power hungry (per unit of work) than new tech. Sure my old Atari computer used very few watts compared to my modern 50 core server (I'm not sure what GPU), but the modern server can do a lot more per watt.
> developing less new stuff, and just slowed down the economy for a simpler life.
To each their own - I would find that world boring. I enjoy camping for a weekend, but I'm very glad to get back to modern civilization and there are plenty more luxuries that I want in development.