Valve released a new stable Steam Client update that that enables hardware acceleration on Linux and brings an overhauled user interface.
@VulcanSphere Apparently enabling it on an system with an NVIDIA GPU may cause X11 to crash. Sounds about right knowing NVIDIA.
It does not crash for me, but the UI does not appear anymore and Steam gets unusable in the Steam Beta. If anyone else is in the same position like me, then just start with commandline
steam -clearbeta
and disable the option “Enable GPU accelerated rendering in web views”. This problem only happens with the option enabled in the new Steam Beta (and probably because of new Nvidia update too). But it works on stable branch of Steam.Issue: https://github.com/ValveSoftware/steam-for-linux/issues/9630