There are now several solutions for org-mode on mobile. Organice, beorg, org-web, Orgzly etc.
Wait - I see that org-web says it does sync with Google drive, so I will try that out. Seems like I can use it by self hosting and not requiring giving google credentials out to some scary startupm (or large corporate entity I don't want to trust either).
Thanks for the tip!
More fundamentally, if you (anyone reading) can think of any easily usable way to sync files between devices, I think it might not be too hard to get Organice/etc. to support that as yet another backend.
There is also a guide for android https://orgmode-exocortex.com/2020/04/28/voice-capture-org-m...