I think it's more than phone hardware is still really locked down/non standardized, so there aren't a lot of viable options to get alternatives on there without also being a hardware designer and having the bank to go with that. Need a big country to force a standardization on the hardware interface/bios and an opening up similar to what we have in pc components and this will get a lot more interesting. Sadly the chance of that happening is near zero and the interests of google and apple lie in more lockdown, not less.