HTML and CSS are go-to strategies not just because the web is the target platform for probably most if not almost all user interfacing software these days, but because HTML and CSS are very forgiving. Native UI frameworks are written by software engineers who demand type safety and XAML-like features which convert declarative syntax into imperative/object-oriented C#. The truth is that the vast majority of people who work on user interfaces are not the kinds of software engineers who enjoy this; HTML's model of creating arbitrary blobs of flexible dom nodes (and then using javascript to handle user interactions) is a lot more pleasant than getting compilation error after compilation error in XAML and having to google how the hell you display a set of items in a ListBox, only to have to filter through 4 or 5 different slight variations in the proper types between WinUI 3, WPF, UWP, and Maui.

Native desktop software will never beat web browsers as long as you're forced into using the framework's model for structuring your data and code. 13 year olds learn HTML, CSS, and Javascript, that should be the target for usability with native UI frameworks