Swing underdeveloped? You have been misinformed. The entire JetBrains suite is built in Swing and is top of the line. Swing is under active development, has a strong third party ecosystem, and is rock solid. You can do anything you want to do in Swing, and it is a joy to develop with (unlike any/all of the web front end nightmares).
What .NET GUI libraries are you referring to because anything other than WPF is tetering on "not a good idea." Have you built anything in Swing, WPF, Winforms, Xamarin Forms, or MAUI? You should give them all a serious test drive and get back to us with some informed comments.
What .NET GUI libraries are you referring to because anything other than WPF is tetering on "not a good idea." Have you built anything in Swing, WPF, Winforms, Xamarin Forms, or MAUI? You should give them all a serious test drive and get back to us with some informed comments.