ninjanoir789 As mentioned above GrapheneOS can only be installed onto a Pixel device. The reason being that it is only Pixels that support alternate OS and allowing them full use/access to all the hardware security features.
Samsungs hardware offers a certain level of parity that could be utilised well by the project however Samsungs priority for their devices is not to sell them as references devices for developers to take advantage of but as enterprise devices.
Their focus on enterprise and reassuring corporate customers means that they implemented Knox and efuses that result in all hardware based security features becoming locked out to any OS you flash on it, regardless of the bootloader state (locked/unlocked).
No other device manufacturer meets or exceeds the quality of the hardware or software/firmware on offer from Google as it stands.