At least here, in a very low-end system, Fedora just freezes when ram is full, it's not as smooth. On Windows, there was a ton of problems, but in general, this never happened. Windows would increase the "swapfile" to 20gb, but would never let the system completely freeze.
My guess it's just the default kernel settings that Arch use instead of Fedora.
Arch uses zswap, while Fedora use zram... there's other stuff as well.
It's linux in the end, so you could just change several settings on Fedora... But then... why if you can just install arch?
I think some people are very used to high RAM devices, and doesn't realize these days how some distros can be very bad on low-end systems.
Like, packagekit on Fedora it's a ram hog (and they acknowledge that). Windows these years been bad, but the situation in some linux distros is not great either.
What Linux does better, it's respecting user choice and UX.
I have the same experience on Fedora, and most distros. Arch is the only distro that it's 100% smooth for me.
OpenSuse comes second.