That is not why it failed.
It failed because the market of Linux native games was minimal and at that time compatibility tools like proton didn’t exist and wine was nowhere near sophisticated enough and required too much fiddling to get to work, especially for the layman which steamos very much was and is targeted towards.
Being based on Debian is not one of them, and any others are honestly made irrelevant by the gave that a gaming centric OS couldn’t run 99% of the games out there