I made a separate user for using Steam (and other games), and it involved a little bit of routing when it comes to X11 and PulseAudio. My reason for doing so was primarily because of how games create many dotfiles, and I wanted my home folder clean.
https://wiki.archlinux.org/index.php/PulseAudio/Examples#Pul...
Forgot exactly what I did with X11, but one part of it was having an environment variable that used my main users XAuthority
E.G. [gamer@mycomputer]$ echo $XAUTHORITY
/home/notthemessiah/.Xauthority
"Those who do not understand UNIX are condemned to reinvent it, poorly." -- Henry Spencer, programmer
This goes doubly for "containers" not understanding chroot/jails.
If only chroot was enough, noone would be investing their time to the cgroups, namespaces, LXC, Docker, etc... :-)
Containers provide chroot-like behavior for more than just the filesystem. Processes, user IDs, network interfaces... Chroot is filesystem only.