Phone is an app made by Google that may offer more features and settings compared to the average default Android dialer. It is normally only exclusive to Pixel and Android One devices. However, XDA contributors now claim that it can work when downloaded onto some other handsets.
https://www.notebookcheck.net/The-Google-Dialer-is-found-to-be-compatible-with-a-greater-range-of-devices.461038.0.html
No luck with the ROG Phone II running Android 10. I was hopeful when I saw Zenfone 6 works with it. I get "Your device isn't compatible with this version" at the Store and "App not installed" when running the apk.
Google Fi works buts is practically neutered on this phone. I'd hope for better with the stock dialer.