How are the packages more tested than on Arch? Both systems have multiple testing stages in place, doesn’t it? In Archlinux there are 2 more stages before it lands on the actual end user. Sometimes one has to wait long time, in example for me RetroArch was updated after 6 weeks after official release. That’s not bleeding edge at all. Only the system core files get updated extremely quick. But that’s only about updating new packages.
The “leading edge” term of Fedora is about a total different aspect. It’s leading, because Fedora adopts certain technologies first, before even Archlinux adopts it. In example Pipewire. Archlinux waits a bit before the technology is adopted widespread, while Fedora is leading and adopting it early. And that has nothing to do about how often the packages itself get updated. People often mixup these two things (and so I did probably).