These instructions are currently for Fedora 30. I'll update them over the releases if anything changes.
Press the Win/Super key, type software
and press Enter.
Click the Menu Button (☰) and choose Software Repositories. Now enable "Third Party Software" and "RPM Fusion ... Steam"
Press the Win/Super key, type terminal
and press Enter.
sudo dnf update --refresh
Also it doesn't hurt to reboot to make sure you're on the latest linux kernel.
sudo dnf install steam -y
You can either open it from Activities or press the Win/Super key, type steam
and press Enter.
Accept the agreement and it'll download the latest version of Steam.
Feel free to comment below.
That's odd, it worked on Fedora 31 for me, installed it fresh just now. I wonder if there's something odd happening with your repos.
Try installing all your updates first, also check what repos you have enabled. If you upgraded from an older version of Fedora maybe theres some old repo thats messing things up.
There might be some info on this page that could help - https://forums.fedoraforum.org/showthread.php?308393-dnf-fails-to-update