True, but the average Joe won't install that way.
Discussion
I was answering to someone who said they use GrapheneOS.
Yes but obtanium is play store. I can also install sandboxed play store on graphene.
I really don't want to use/ depend on any Google services, sorry
Obtainium is on GitHub and on the F-Droid
It's an "app store" where you "search" for repos of open source projects you want, and it monitors, grabs, and installs the apk's they bundle into releases for those repo.
Tradeoff: there's no vetting of bad software, it's all on you
Benefit: there's no censorship; it's all on you