Go for Calyx or any other android distro, they have zero difficulties in supporting more devices.
Personally, I wish there was an open/libre device on the market that GrapheneOS could target.
You mean, Pinephone and Librem 5?
The last cellbrite leaks show it as more secure against attacks from le than the current iphones, and that's more important to me than abandoning google hardware.
Also: Android. If I didn't need Android/iOS apps, I'd be using a Nokia 3210.
Waydroid has a very outdated fork of Android with the privacy/security model largely disabled. It has poor Android app compatibility. The apps are no longer isolated from each other and the kernel is far less protected from them.
It's not our fault that the only other devices providing the security features we need don't allow GrapheneOS to be installed or to use those features. Massively lowering our standards and using low security hardware missing the basics we depend on and have built major protections around wouldn't make sense. It's not what GrapheneOS exists to provide. People can use LineageOS if they don't have the same priorities we do.