Despite some weird architecture choices (binders are some weird ass things to handle), the deep changes to Android make it a tolerable OS for mobile purposes. Using X11? Sure, I love display servers that choke on high DPI and cannot do half the things modern compositors do efficiently.
LiveData is not part of the UI framework but merely a tool to provide updates to be listened to on the main thread. It's also half deprecated and you should probably be using flows instead. Why is it here? Because half the GUI toolkits on Linux are either absolute pieces of shit (GTK lol) or simply not enough.