There is putting your Chromebook in developer mode which removes safety checks and a way to use GNU/Linux on a CB. You then can install Crouton.
But then there is putting a CB on the developer channel or the Canary channel which is completely different.
I am currently using both as I can then see what is happening with the host OS while using the new VM capabilities with my PixelBook.
You have a GNU/Linux kernel which you can do whatever you want.
For more info visit Reddit and the Crostini subreddit.
You can use Steam or really whatever.
Even GUI works as forwarded to ChromeOS. So start xclock and opens.
What is graphics performance like for the guest ? Does this use gpu virtualization (somewhat supported for intel gpus in recent kernels) ?
But realize this losses cross platform support inheriently so you would have to use ARM gnu/Linux binaries.
Just visit the subreddit.