Thank you for the lead!
It seems that only -updates repos were installed somehow; however most likely it was I who removed non-updates files from yum.repos.d and forgot.
I managed to resolve the issue by removing trailing repos via sudo yum remove rpmfusion-free-release rpmfusion-nonfree-release and installing them again. Then I installed ffmpeg by running sudo dnf swap ffmpeg-free ffmpeg --allowerasing. Thanks again everyone