I think XMPP is great, but if we can’t get those closest to us to even use Signal, I don’t think an even more convoluted system will be easier. What makes Prav different from all the other XMPP apps? Edit: Never mind. The convenience of using a phone number is the difference. Which is no doubt easier.

They didn’t specifically disregard budget phones. The budget phones just won’t have the hardware required to meet GrapheneOS requirements. They’ve states that as the next gen flagship hardware trickles down to the budget phones, there’ll be more options.