Not exactly on a smartphone fully, but I use Samsung Galaxy S24 and absolutely love Samsung Dex. I use a Nexdock (although I will probably switch to a standalone display with a better bluetooth keyboard/touchpad combo in the future)

Termux, with code-server works very well. There are a few things that are missing. Haven't been able to get pytorch to work, but thats just a matter of figuring out how to build it from scratch.