[dragontamer]

I actually have an old phone that I used as a remote-control for my home-threater PC. No connectivity needed, but the phone did everything I needed. Move the mouse, act as a keyboard, and mostly raise volume / change channel.

Phones are computers. Even if you remote all connectivity to the outside world, they still function as well as any PC from the early 90s (or earlier). A huge amount of compute power, tons of storage, etc. etc.