Hello @byte1024, this should also be mentioned to Fedora's package maintainer(s) for glibc.
Will do.
Additional notes
Its possible for dnf to lose the old packages so that undo/rollback fails. Going to fedora updates site, manually downloading the old ones, then forcing rpm install of old packages may be required to get Steam working again as I'm sure others may run into this problem. Annoying but it works.
glibc-2.30-8 is the last version so its -9 or -10 that breaks Steam.
Separate install of Wine had libc.so.6 in /usr/lib/wine/ for some unknown reason (not there on fresh install of Wine) which conflicted with Steam and glibc-2.30-10.
Removed Wine, removed /usr/lib/wine, re-installed Wine, and both Steam and Wine exist. Steam now starts along with glibc-2.30-10.
Nothing extracted yet.
Your system information
Steps for reproducing this issue:
(downgrade glibc and Steam starts again)