Officially, Valve states that the .deb from steampowered.com or the Flatpak are the only supported versions of Steam. The packaged version on rpm-fusion is made by a 3rd party and valve has no control over what dependencies are bundled.
Please retest with the flatpak version of steam and attempt to reproduce. Or install Ubuntu LTS as the Readme on this repo suggests.
There is an open pull request to update the readme to better outline Steam's requirements. Please read, and cross reference the requirements against what operating system you're using on your workstation: https://github.com/ValveSoftware/steam-for-linux/commit/72b3eae88920635f16b30e385da0998c29f53411
Since you're running Arch, presumably you're using the Steam client that was bundled by an unofficial 3rd party. What steps have you taken to ensure that all of the client's dependencies are met on your workstation? Have reported the issue to the individual who compiled the application for your operating system? Valve does not have control over what's in the AUR, and ultimately on your system if you're running Arch
officially doesn't make much sense... as the binaries run are not from the distro... steam updates itself - and downloads new binaries into ~/.steam/Steam/.... and in there there literally are a whole set of libraries and binaries only supplied by steam downloaded right from valve - not from the distro. yes - it will rely on (indirectly art runtime) on host libs like the x libraries, gtk etc. ... but these are the same deps any distro would ship. so here the package comes from is not relevant really as it ends up running what valve ships and updates installed in $HOME.
it'd be pretty trivial to check to see if you see the same thing - a lot less time than me installing ubuntu on bare metal and reproducing a steam install and so on... just strace -p $PID_OF_STEAM and see so you see the same? do you see the same when not in gnome. i have a friend who sees just this on a different distro with i3 + x. i see it with arch and enlightenment + x. it smells to me of some work-around code doing high-rate polling on something it probably shouldn't... but as steam has no source... i can't check.
Nothing extracted yet.
Your system information
tar -zcvf ~/Desktop/steam-logs.tar.gz ~/.steam/steam/logs]Steam, sitting there with no windows open just in my systray (notification area) is endlessly waking up consuming cpu at a high rate. At least every 5ms it's polling stuff for no good reason. This means it consumes power all day at what I'd consider an unreasonable rate. Attached is an strace of my steam process. the fd's it does a recvmsg() on with EAGAIN are all separate connections to my xserver... history/experience suggests this may be a XCheck*Event() or XPeekEvent etc. like call. I can't say much more as I don't have source code. I guess I could try digging a lot more....
See strace snippet:
steam.log
Steps for reproducing this issue: