We thought about this a lot, and why rollout expensive phones with performance an AI features not really used outside Google Play Services when you have amazing and available Pixel 6 phones.

Also, for price of Pixel 8, you can get 2.5 Phi Daisy (Pixel 6 + GrapheneOS + Free Unlimited Support) https://phi.company/daisy  

 Because you should never buy a phone with Graphene OS preinstalled when you can change the ROM easily by yourself. 😉 Why should one trust a thrid party...