Third sentence:

Flatpak serves as the primary application distribution method for image-based operating systems including Fedora Silverblue, openSUSE Aeon, SteamOS, and GNOME OS. It is the preferred format for major ecosystems such as GNOME, KDE, and elementary.

You don't know the infamous hacker packaging method named Flatpak?

These articles are meant to be read, that's the premise of posting them.

Flatpak is a mature project and the best option that exists on GNU/Linux today, but its security and sandboxing features still trail behind those of well-funded proprietary platforms such as Android and iOS.

I mean you could read the linked blog post where they explain it

It's for security sandboxing features