I miss Arch occasionally but I don’t like being responsible for the operation of my machine; I would rather delegate it to the operating system. ;)
The good thing about Ubuntu is that it’s the default “Linux” (distribution) so whatever you are looking for, there is likely an AskUbuntu question, a .deb package, a blogpost, or a mailing-list entry to help.
I don't know if I agree about software availability if you take AUR into account.
Also, it is dead simple to make your own PKGBUILD script for arch, but last time I tried looking into making a .deb my eyes rolled into the back of my head.
The good thing about Ubuntu is that it’s the default “Linux” (distribution) so whatever you are looking for, there is likely an AskUbuntu question, a .deb package, a blogpost, or a mailing-list entry to help.