Looks increasingly unlikely that there will be convenient ways to have the best of both those worlds in a single device. For now it is somewhat possible with Android, but the experience keeps getting worse.
Maybe 2 phones are the way forward.
Maybe a PAYG phone which stays at home on my network for particular needs like banking.
Then a standard phone which is essentially a GNU/Linux distro.... mmm... Emacs on my phone sounds lovely!
Meanwhile, you can use it in termux if you are on android right now.