Manufacturing probably way outshines the usage. And, the side-benefit of using old machines with say NetBSD or OpenBSD etc is that it makes people realize that they don't NEED new modern shiny hardware. I am still daily-driving a x220 on the road (it gets 99% of my stuff done) and at home I am using mostly a slightly upgraded T480. So a 15 year old and a 8 year old laptop. And power consumption wise, my T480 lasts about 17 hours on a charge. That is about same time I'd get out of a modern M3 MacBook Air.

With a bit less performance? Sure. But for my use-case it works. And more people realizing that might actually be a good thing.