Very many.

Amiga 1200. Released in 1992, got update to AmigaOS 3.3.2 at 2023 https://www.hyperion-entertainment.com . That is 31 years.

My wife uses Vista era laptop, from 2007. Still works great at 2023, changed it to have SSD disk and 8 GB RAM, running newest Linux Mint.

Newest Windows, macOS and ChromeOS only works on newest devices. After that, just install Linux. For example, 2 weeks ago I installed Debian 11 to Chromebook https://github.com/xet7/chromebook

Answering to myself, there is article about locked iPhones. Same problem is with Android.

https://coloradosun.com/2019/04/17/recycled-iphones-trashed-...

Problem is only, if manufacturer does not allow to:

- Install alternative OS

- Change or upgrade RAM and harddrive

- Change battery

It is possible to do all or some of that to some Chromebooks, there are videos at YouTube. It depends on model.

At that article, there is complaining about Chromebooks and reparability. Where are similar articles about smartphones?

Mac and Windows laptops will probably run the latest OS for more than 8 years. Still, I don't see why a school should buy a more than 1yo Chromebook, so that leaves 7 years of support, which is fine. Most likely dies from 2% milk before then.