Doesn't the Steam Linux Runtime have a problem in the other direction though? Games are using libraries which are so old that they have bugs which are long since fixed or don't work properly in modern contexts. Apparently a lot of issues with Steam + Wayland comes from the ancient libraries in the Steam Linux Runtime from what I have been able to find out from googling issues I've experienced under Wayland.
There's also a variant of this container that contains a forked version of Wine for running Windows games as well.