nostr:npub1m5s9w4t03znyetxswhgq0ud7fq8ef8y3l4kscn2e8wkvmv42hh3qujgjl3 nostr:npub1kl8e7s48j6cfr6zrmn53n5l0fsxustszj3fwmu9ahn0tnm9e8euq80u2uq nostr:npub1m2mvvpjugwdehtaskrcl7ksvdqnnhnjur9v6g9v266nss504q7mqvlr8p9 nostr:npub14slk4lshtylkrqg9z0dvng09gn58h88frvnax7uga3v0h25szj4qzjt5d6 You can see from the high quality third party comparison at https://eylenburg.github.io/android_comparison.htm other Android-based OSes are far different and not focused on privacy and security in the same way. That's why they support devices with poor security.
Discussion
nostr:npub1m5s9w4t03znyetxswhgq0ud7fq8ef8y3l4kscn2e8wkvmv42hh3qujgjl3 nostr:npub1kl8e7s48j6cfr6zrmn53n5l0fsxustszj3fwmu9ahn0tnm9e8euq80u2uq nostr:npub1m2mvvpjugwdehtaskrcl7ksvdqnnhnjur9v6g9v266nss504q7mqvlr8p9 nostr:npub14slk4lshtylkrqg9z0dvng09gn58h88frvnax7uga3v0h25szj4qzjt5d6 GrapheneOS only supports Pixels because Pixels are currently the only devices where an alternate OS can provide a high level of security. Other devices with the listed security features don't allow another OS either at all or securely.
Can you elaborate as to why that is the case?