Yeah it would be nice to break away from the google ecosystem and install GrapheneOS on whatever device I like-

GrapheneOS has official production support for the following devices:

    Pixel 9a (tegu)
    Pixel 9 Pro Fold (comet)
    Pixel 9 Pro XL (komodo)
    Pixel 9 Pro (caiman)
    Pixel 9 (tokay)
    Pixel 8a (akita)
    Pixel 8 Pro (husky)
    Pixel 8 (shiba)
    Pixel Fold (felix)
    Pixel Tablet (tangorpro)
    Pixel 7a (lynx)
    Pixel 7 Pro (cheetah)
    Pixel 7 (panther)
    Pixel 6a (bluejay)
    Pixel 6 Pro (raven)
    Pixel 6 (oriole)

The GrapheneOS project is working to correct the problem. For more information see this comment written 18 days ago:

https://old.reddit.com/r/GrapheneOS/comments/1o32gpg/b/nivsx...

It's been discussed previously, but pixel devices are chosen for hardware security feature sets. Other devices are either not compatible/open enough to use or a security downgrade.