To supplement the other reply, a big difference is how they approach the cross platform UI. Xamarin Forms/MAUI is effectively an abstraction layer on top of th

To supplement the other reply, a big difference is how they approach the cross platform UI. Xamarin Forms/MAUI is effectively an abstraction layer on top of the Android UI Toolkit and CocoaTouch. Uno is its own implementation of a UWP compatible UI that renders everything onto the screen using Skia. You get the same affordances of cross platform .NET, C#, and XAML. Uno gives you pixel perfect cross platform UIs, but loses the native feel, which MAUI preserves, at the cost of writing more platform specific renderers.