Once, I found myself coding in a chat application using mobile phone's onscreen keyboard while attending my mom's friend's daughter's wedding party because of some emergency.
Brick + pencil is the perfect metaphor for any kind of frustration-causing depowered productivity tool
So why do people use screen keyboards at all? It's such a frustrating experience! You'd think they'd carry laptops around everywhere instead, and yet they don't.
For a few words, it's better than carrying around a dedicated keyboard.
For more typing, I carry around my own standard 104-key keyboard.
No good alternatives. For years, I had smartphones with slider keyboards. Now, I carry a foldable bluetooth keyboard in my bag. Onscreen keyboards are for emergencies only. But a lot of people view lugging the keyboard as unacceptable.