Actually MacBooks get 6/7 years from when Apple stops selling them. In contrast, the timer starts as soon as the first Chromebook with that cpu is released. It was a nasty surprise when I found that out
That is terrible. So they'll never create a device that is good enough that they'll sell for for 6 years unless they sell something they don't support.
Other than that, few vendors sell 6 year old computers. Since Apple is often put up as model company here: 2013 had the iPhone 5s which was sold until early 2016, and the end-2013 MacBook Pro (based on Haswell) which was replaced by its successor in 2014 (based on Haswell-Refresh).
I didn't realize that. When I think about how many schools have bought racks of Chromebooks and how long they keep them in use I realize that there are lots of kids out there using insecure machines. And all of them have cameras and microphones. Yikes!