Stefan Monnier:
it's android without the "I'd like to call home' parts, if you choose the bare install. You got to use fdroid or similar for package installation then.didn't find any for debian but maybe lineageos > https://lineageos.org/LineageOS is nice, I strongly recommend it, BUT it is Android (just a nicer distribution of Android), so it doesn't fit the requirements, I think.
readU Frank