I prefer appimages, it feels much more “open” than flatpak ever will.

Flatpak: install flatpost and flatseal.

Appimage: Download appimaged appimage to ~\Applications and run once.

then

Flatpak: Go to site for cool software I heard of, see it’s flatpak with a link on the page. Click link, wait for flatpost to open, wait for flatpost to update repos, get cool software and possibly another copy of mesa and gnome compat stuff, then head to flatseal to fix drive/device permissions as needed.

Appimage: Go to site for cool software I heard of, see it’s an appimage, download said appimage to ~\Applications, appimaged automatically loads in a desktop entry and we’re done.

As far as updates, all the appimages that are in active development that I use, offer auto-updating when I open them, plus I’m not reliant on a centrally-controlled repo of the packages (which if it dies, takes all updates with it).

I feel appimage would be an easier adoption for people fresh to linux, as it follows the same model as windows or macos (download executable, install app), even for the initial setup of appimaged.

And either way, there’s no “winner” here, if we’re playing that game, native installs still win. Every distro supports (and uses) those by default, except for ubuntu, who has money on pushing snaps.