I would rather compare appimage to PortableApps, except it bundles dependencies too.

Native then Appimage then Flatpak. Security is the same in the end, but in Flatpak with extra steps, while Flatpak has a huge framework that can fail too.

Is there a question in here somewhere?

No.

Of course you have stuttering if you use that in the screenshot as your desktop.

Joke aside, wasn’t there a real desktop environment that uses a game engine for rendering?

Sorry, no, don’t want that in a terminal.

Discrimination against people that can’t support themselves.