Liu declined to provide a timeline for the project, but did confirm it would be enabled by Chrome OS’s Linux compatibility. The Steam client would, presumably, run inside Linux on Chrome—a platform for which it is already available. Liu implied, though would not directly confirm, that Google was working in direct cooperation with Valve on this project.
Currently, it is possible to install the Steam Linux client on Chrome OS using the Crostini Linux compatibility layer, but there’s no official support, and performance has been pretty lamentable even when comparing identical Linux-native systems to Chrome.
Source: https://www.androidpolice.com/2020/01/17/exclusive-google-is-working-to-bring-steam-to-chrome-os/
Those that currently run Steam on Chomebooks (as a hack), do not get hardware acceleration, therefore the performance is not there. This has to do with the Google setting up a VM on Chromebooks and then in that VM running a cut-down version of Debian, and further in there running LXD. All that is really good for security, but they just need to find a way to give access to hardware acceleration to the applications running in LXD.