I'm not sure it's so clear. On one hand, businesses will continue to purchase computers and sell them in lots every few years. On the other, every computer purchased from some other supplier is one less made by someone else. What's important about a computer is it's suitability for purpose, which is not necessarily the same thing as fastest / latest / cheapest / whatever. If my purpose requires modular expansion, my choices are this thing and Framework. Neither of which I'm going to find inexpensive used. I can think of a lot of scientific and engineering data logging applications that would be great for. And a machine like that might serve 20 years if it works well at the task. I've seen a lot of machine controls still running Windows 98.

https://www.clockworkpi.com/home-uconsole is another great example of a machine I've seen people mod into all manner of special-purpose device that wouldn't work as well with a used business laptop.