I can do full fledged software development complete with fully desktop-equivalent Neovim on my phone.

That said, it's really not a pleasant experience. The CPU in my phone is pretty fast all things considered, but it still takes several times longer to compile a project than my laptop does; having this little screen real estate sucks; and since Termux doesn't enable predictive text on the onscreen keyboard (and predictive text is worse than useless when writing code anyway), the best I can hope for productivity wise is a keyboard like Hacker's Keyboard or Unexpected Keyboard that at least has functions like Esc built in. When I have a Bluetooth keyboard, I'm about half as productive as I am on a laptop. When I don't, writing the same program takes ten times as long. But it does have all the same features my desktop setup does, and it is usable in a pinch.