If you use WPF you can have the Mica backdrop underneath your WebView2 content and set the WebView2 to have transparent background color, which looks nice and a little more native, fyi. Though if you're doing more than just showing the WebView maybe isn't a choice to switch.
I like the idea of using a transparent background in the webview. That would compose really well.
The primary motivation for winforms was getting easy access to OS-native multiline input controls, clipboard, audio, image handling, etc. I could have just put kestrel in the console app and served it as a pure web app, but this is a bit more clunky from a UX perspective (separate browser window, permissions, etc.).
