Even though different Linux distros are often fairly close in terms of real-life performance and all of them have a clear advantage over Windows in many use cases, we can’t reject the fact that Arch Linux has undoubtedly won the competition. And now I’m so glad to have another reason to proudly say “I use Arch btw”
::: It was a joke of course :::
It seems quite likely that, in the Arch ( EOS ) system at least, a tonne of that space is being used up by the package cache. By default, the system keeps copies of the packages for all software you install. This can indeed take gigs of space but it has nothing to do with your running system. A simple command purges them all and reclaims the space. You would obviously want to do this before reporting installation size. I bet he did not.
Arch package spliting is not as hard as Debian/Fedora.
But IMO, it’s because Fedora uses BTRFS with compression enabled.