This feels super entitled to me. GrapheneOS Devs have a mission and they get to make that. You get it for free and if you like it you can give them money. If they don't support the hardware you like you are free to fork it and get it to run yourself.
And if security isn't something you care about but privacy is and you feel like there's a difference here you can still install /e/os or lineageos and similar on the fairphone.