I'd argue: whether using a stack like this or not, the app deployment story on Linux is absolutely atrocious. There are people in this thread who say they're never going to use Flatpak, some for valid technical reasons, others for more ideological reasons. And that remains the case, no however flawed you or I might think those reasons are.
So if an app developer wishes to reach those users, they can't rely on this stack to do it. You could ignore those users, sure, but at this point, why are you making a Linux application? It would be much more attractive to deploy on Windows or Mac. If you're trying to convince people to make Linux applications, you need to make it attractive and painless. But you can't solve social and cultural problems; problems of ideological differences, no matter how much you try to patch around it with new technology.
So if an app developer wishes to reach those users, they can't rely on this stack to do it. You could ignore those users, sure, but at this point, why are you making a Linux application? It would be much more attractive to deploy on Windows or Mac. If you're trying to convince people to make Linux applications, you need to make it attractive and painless. But you can't solve social and cultural problems; problems of ideological differences, no matter how much you try to patch around it with new technology.