There are android distributions like Graphene OS and LineageOS that are completely open. The problem is application developers that specifically restrict their apps to only run on google/apple certified hard-/software
But Graphene and Lineage don't support on most phones. If phone makers were to be more forthcoming and cooperative, they could get one or both of those, or some mobile-phone-oriented Linux distro, to work and then Bob's our uncle.
But Graphene and Lineage don't support on most phones. If phone makers were to be more forthcoming and cooperative, they could get one or both of those, or some mobile-phone-oriented Linux distro, to work and then Bob's our uncle.