This phone has its own built-in VPN and doesn't use Android or iOS

I wish some comparison was made to other phones that fit the title. Maybe linux phones like Pinephone or Librem, or other Android-derived OS phones like Pixels with GrapheneOS or CalyxOS . If the company fails, any chance of using a replacement "Android ROM", like AOSP or PostmarketOS? For that matter, mentioning the ~$300 price tag would be nice.