GOS is broadly compatible with most phone use cases out of the box--chat, mail, browsing. A Google Play profile lets me use almost all apps (including my bank apps, but I understand that's not true for everyone).

In principle I agree about a Linux phone, but the gaps are much greater. I am also sympathetic to the GOS team's arguments that sandboxing on Android is better, and important on a device that allows control of essentially my whole life (2FA apps etc.)