and numerious other Situations where Flataks (and Snap's) were a Problem because of it's Format and limited Permissions, I would suggest to change the default Package Format in Gnome Software to the .deb/APT Package. That can avoid Permissions-related Issues. Especially for new Users who might not know about that.
To be clear: I don't want suggest to ban Flatpaks. I only want suggest to don't set them as default Package Format.
New users (like me) have to Google the differences:
Synaptic (GUI) and APT (CLI) are traditional, distribution-specific package managers for DEB files, offering tight system integration and small file sizes. Flatpak and Snap are universal, sandboxed, containerized formats (Flatpak faster/safer, Snap better for CLI/servers) designed to work across all distributions, often requiring more disk space.
Key Comparisons:
APT / Synaptic (Traditional): Best for core system software and stability on Debian/Ubuntu-based systems. They manage dependencies across the whole system, which can sometimes lead to library conflicts, though they are usually faster and smaller.
Snap (Canonical/Ubuntu): Sandboxed, auto-updates, and excellent for both GUI and CLI apps (e.g., server tools). They are tightly integrated with the Snap Store, which is not fully open-source.
Flatpak (Community-driven): Focused on desktop applications, offering better security sandboxing and faster app startup times than Snaps. It is generally more popular for application sandboxing (e.g., Flathub).
...so we then have to ask them how they installed the app when they report issues here. Sometimes having them list their Flatpak's and Snap's to find out. There must be a better way.
AppImage seems to be the best method of installing apps. The problem is that quite a few don't get integrated into the OS with icons in the Zorin search and in the dash. But that could be overcome by integrating something like GearLever in the OS.
Other than that I think *.deb is what I've had the best experience with.
.deb or Zorin native apt, are more compact than Flatpak and Snap when you have limited drive space.
Now we have to ask them how the app is actually installed, not how they think they chose to install it. As some .debs are vectored to Snap or Flatpak versions. This is horrible. Makes Windows look saintly (well maybe not that good).
Did you mean App Image? If not I think you mean APT. Aptitude is anothet option to use via Terminal.
In respect of Flatpak, this is where Q4OS shines. It has a Software Installer shortcut in its Welcome screen and Flatpak is an option to install, not a default presence.
Personally OS's that include Synaptic Package Manager, and not a post install necessity are better. Devuan, MX-Linux, PCLOS, PCLOS Debian.
Just as you did with the dashes to make a strikethrough, replace the four dash marks with the tilde mark, instead and that will give the strikethrough.