That's seriously horrible. There are 5+ open source android apps that I use and want to continue using that are not available on Play Store, but rather through alternative stores (like Zapstore, Obtainium).

If I get a phone with preinstalled Graphene OS (like the upcoming Motorola phone), then does it avoid this stupidity? Or even with Graphene it prevents me from installing apks?

Graphene allows APKs