I think Java was almost killed by not having native look and feel in Swing. There is probably still a lot more desktop applications written with native Windows

I think Java was almost killed by not having native look and feel in Swing. There is probably still a lot more desktop applications written with native Windows look and feel than with Qt or Java. It is still a problem with mobile apps that users can feel confused over some gui's that are made with html+css (or something else) and does not follow the native look and feel for the platform in question. It will probably get better over time but it has been an obstacle for many, many years.