The survey comes direct from Valve's Steam Survey. Potential bias aside the Steamdeck alone is estimated at 40%. Arch and Ubuntu ~8% each.
Is there any other trustworthy metric of all "Linux Gamers" out there? I'm curious how much using the Steam Client effects or tilts results towards systems that easily run Steam. Self selection at it's finest. My logic side knows that with only a 1.5% rounding error to the total "PC" gaming isn't market significant. I should be happy with the trend.
I own a Steamdeck. But it's like how my friends use their Nintendo systems. As an extension of my PC windows I was already personal project time with SteamOS and SteamLink. Point is, I wouldn't consider myself in the 1.5% even though I game wherever.