1. If you haven't already discovered Termux, do. It's the one thing on Android that doesn't manifestly suck.
2. I don't mess much with Python, but Termux + python + pip allowed me to install youtube-dl and be able to download and play videos (from numerous platforms) on-device rather than streamed-only.
leouieda.com/blog/scipy-on-android.html
It worked as advertised. Granted, it was a symbolic gesture, since I can't imagine doing any real work on my phone, but it answers the question of whether I could live with an Android tablet as a laptop replacement. My definition du jour of a "real computer" is anything that can run Jupyter. ;-)
Being kind of ignorant of the inner workings of this stuff, I was quite impressed.
The one main problem involves shortcut keys. Chrome OS intercepts certain key presses, such as "CTRL N" or "CTRL T", and routes them to the browser. Makes emacs / vim a little annoying, but a Chrome OS dev assured me this was on the "to fix" list.
I think it just depends on the size of the phone. My current phone has a 5.5" screen and since the dev environment I use was updated to make best use of it, I find it quite usable for programming where my previous 4" device really wasnt, but it's close to the lower bound of what is usable.
It's actually an iPhone 6+ and I use Pythonista, but my point is a large enough phone can reach a level of acceptability and I don't think that's a platform specific point.