It's nice to see this project coming to fruition. I just find it sad Gnome/KDE/Linux are not supported. Still there's always the possibility of doing an Electron-like app using Blazor for Linux apps.
Specifically I made a small application with F# and the FuncUI library https://github.com/fsprojects/Avalonia.FuncUI
So far the most complex real-world application I've seen is Lunacy: https://icons8.com/lunacy
It's nice to have something like this out there. It definitely eased my apprehension of using the platform on the grounds of it being immature.
I've a decent amount of experience with Xamarin (Native and Forms), and so far I've had 1/100th of the build issues with Avalonia.
I am excited to try out MAUI however and see how things have evolved!