I have been using UBports on my primary phone (Nexus 5) for the past year. It has been mostly great. All the expected things such as phone calls, text and web browsing work just fine. They have an app store with a fair number of apps, although obviously nowhere near to what is available for Android. Updates for the OS have been quite regular every few months. I have previously been using LineageOS on Nexus 5x, but personally I find UBports better. It is much closer to a real Linux distribution than Android, while still being a pretty usable mobile OS.