The Nexus 5 was released in October 2013 and was on the most up to date version of Android through August 2016. It will continue to get security updates. Plus it will continue to get updates to Google Services (a chunk of what we think of as Android) and the core apps including the default browser. Unlike Apple, Google doesn't really do the 'you get the next version but a bunch of new features are disabled' thing. The fact that Google Services, core apps, Chrome, and other things will continue to get updates does feel vaguely reminiscent of it, though.

> I am not sure why we find this acceptable anyway. When we buy a $300-400 Windows x86 laptop, we also expect it to be upgradable for a decade or so (which is usually possible).

We didn't used to. Not so long ago, keeping the same computer for 10 years would have been a ludicrous idea.

Heck, I got a Dell laptop for considerably more than $400 in 2003, less than 13 years ago. Its screen died 3 years later. I still have it around, but it's not much good without a display.