Flatpak vs native packages. Is one 'better' than the other?

[Pistrie]

So Flatpak is gaining more and more traction, especially with it being the only way for normal users to install software on their Steam Deck. However, are they actually on par with native packages. What are the differences for me as a user, besides Flatpak having the it just works approach?

[BluishHumility]

The very basic and immediately noticable differences are:

• Flatpak will run older versions of packages than what would be available from the Arch repos.
• Flatpaks use a ton of storage space, because they pull in all their own dependencies to use in the container instead of using the binaries already on the system like a normal package would.
• Due to running a containerized version of a program and being a little more isolated from the rest of the system, a Flatpak can often survive an otherwise breaking change to a package or dependency.

If you are curious to learn more, spend some time searching the web; Flatpak (and containerized apps in general) is a topic that is all but beaten to death out there in articles and discussions all over the internet.

[Kayo]

Apart from what Bluish already mentioned, a lot depends on the package as well. For packages for programs that are demanding and that you are going to be using regularly, it is usually advised to do some research between the flatpak and native versions.
Some program makers only "support" their flatpak versions for instance (like OBS). On the flip-side there are quite a few programs that are offered as flatpaks, but you'll typically want to run native instead if you can like Steam.

Edit:
Typically my "rule of thumb" is to try native first, and if I run into issues with installing or running it, to try the flatpak.
Arch usually has great libraries (and package dependencies in general) so it usually isn't an issue for native packages.
Sometimes though, packagers get things wrong in the AUR, so a package won't build. Other times there might be a niche program that takes too long to get from the AUR that would be much easier and quicker to get via flatpak.