Its even worse when you force Firefox to use wayland its icon doesn't even show.
Edit: Oh since everyone now is confused; I only have the flatpak version of Firefox installed yet it doesn't use the pinned icon and doesn't even use the firefox icon under wayland at all.
Using the word OS puts across my point, because when you start packaging your toolchain with glibc and whatever libs you need for your application, you end up with a good part of the Linux file system. Yes there's missing services and so on but they could run if needed.
It's not a virtualization joke, it's more of a "we put flatpak in your flatpak so you can flatpak while you flatpak" recursion joke.