Apologies for self-linking here, but it's not just cool things, in my opinion it could transform humanitarian aid work. I wrote a use-case/short-story about it here:

https://ianso.blogspot.com/2025/11/what-we-dont-have.html

Like using your phone as a desktop computer, when it's connected to a screen and keyboard and runs a full desktop OS. Having a full access to all desktop apps, development environments. Also this, https://news.ycombinator.com/item?id=49201496.

Also, choosing the OS means freedom to choose the interface you like or develop your own (or to pay somebody to do that for you). Freedom to not be in walled gardens.

like running K8s on your old phones?

Calling our friends, maybe? No idea; I've tried desktop Linux on phones years prior and besides maybe being a potential portable cyber security rig it was only a cool oddity.