I definitely don't think it's even the likely outcome, but for Linux to get serious traction this is how it has to start: power users but not the traditional developer crowd start actually moving, and in doing so produce the guides, experience, word of mouth, and motivation that normal people need to do so, alongside the institutional support from Valve to actually fix the bugs and issues.
It remains to be seen if a critical mass will find it usable long-term, but if it were to happen, this is how it would look at the start, and Microsoft are certainly doing their best to push people away right now, although I suspect the real winner is more likely to be Apple with the Macbook Neo sucking up more of the lower end.
According to a speculative blog post by Eric S. Raymond in September 2020, Microsoft is literally moving towards replacing Windows' internals with Linux. Unfortunately, that post is now unreachable, but searching for "eric raymond article about windows being replaced with a linux kernel" finds many third-party references to it and summaries of it.
For example, I have Steam installed on my Macbook pro and I occasionally play a single very simple game there. Does that make me a macOS gamer? of course not. The vast majority of games I want to play don't work on macOS.
I suspect that most of those 5% are just Linux users who have steam installed and play a small amount of games. Some probably just installed it to check what's available and don't play anything.
Everyone I know who is a "serious" gamer, as in exited about upcoming releases of AAA games is using Windows.