I already run Steam in Docker for this reason, with its own home directory mounted as a subdirectory of my real one. Even before games swiping my homedir I was worried about Steam wiping my homedir, as it's already done once in the past. [1]

Though ironically that means I can't use the new Proton runtime thing ("Soldier runtime" I think?) that sandboxes games via user namespaces, because my distro doesn't build the kernel with userns support so it would require me to give the Docker container more privileges.

[1]: https://github.com/valvesoftware/steam-for-linux/issues/3671

> It's not as good as open source but let's be real, you'll never get AAA open source games.

Free software philosophy (the "F" in "FOSS") allows the art and data files (levels) of a game to be proprietary, while keeping the code open-source. Sell the game itself, code comes for free.

https://www.gnu.org/philosophy/funding-art-vs-funding-softwa...

To the best of my knowledge Valve's container system has no relation to Flatpak.

I think it does :

https://github.com/flatpak/flatpak/issues/3797

"Recent versions of Steam can optionally put each game in its own container, using a Flatpak-derived tool named pressure-vessel."