Since you are using radeonsi you may have a conflict between the system libstdc++ and the one shipped with the steam runtime (Although this usually meant Steam doesn't start at all).
cf: https://github.com/ValveSoftware/steam-for-linux/issues/3273
Since you are using radeonsi you may have a conflict between the system libstdc++ and the one shipped with the steam runtime (Although this usually meant Steam doesn't start at all).
cf: https://github.com/ValveSoftware/steam-for-linux/issues/3273