Flutter has three major problems: - Performance: Even on Desktop, animations have jank. Last I compiled samples on Mac, the problem was visibly there. - UX: Text editing immediately feels alien. If Mac for example, you have a text field in a native app and on the side you have a flutter app with a text field, you can tell the difference between the "feel" when you type in each. This isn't necessarily limited to text…
Flutter is mainly a mobile framework. Electron owns the desktop, anyone using flutter on the web is crazy. While you're points are valid, they are kind of irrelevant.
Other than that I agree - Flutter web is not going to be a good choice and that was never really the goal for them, I believe.