Recently switched to using Flatpaks instead of random .debs for a number of apps on my system. /var/lib/flatpak takes up 7GiB, which honestly isn’t that much (even though it’s like quarter of the OS size), given that’s the software I use most of the time.
Was skeptical at first about Flatpaks, but SteamOS showed me that is great at just giving OS developers access to a fully populated app store with minimal work.
Honestly, nowadays I’d say “ability to install flatpaks” should be the criteria on which we decide whether an OS is really “linux” or not (that is, SteamOS is, but Android isn’t).
Edit: Okay. I said something stupid here, my bad. What I was trying to get at is the distinction between Android, etc. and “Desktop” Linuxes like traditional distros, Chromebooks and the Steam Deck. Even though it technically runs Linux, it’s hard to argue that developers for Android are really writing apps that work on “Linux”. Wheras if someone releases a Flatpak version of their app because they think the Steam deck is cool, it works on other distros “for free”.