@Tutanota A shame Google went through with this... Yet not surprising coming from them. The openness of Android served them in the early days of Android to attract people, against big bad "Apple's locked down Iphone". Now it's in their way.
I used to recommend Fdroid to friends and family. Happy #murena_eos user myself (never had a graphene compatible device to try it), but I can't imagine recommending flashing a ROM to just anyone, not everyone is ready to take that big a step.