In their gnome version, during the setup process (first boot, not install), they would prompt for third-party repo and codec (Enabled by default, IIRC).
I think you might have unchecked that? or KDE not offering such experience?
EDIT: NVM, I just checked, and I have never installed the codecs… LOL.
Fedora is notorious for avoiding shipping proprietary software with their distro even at the cost of new users.
I think this might stems from the fact that fedora used to be a distro aimed for advanced users. It is slowly getting better at being new user friendly.
Viclan