To win this console generation and outsell the PS5, Valve would have to sell 85 million Steam Machines (as of today, and likely need to sell 120 million by the end of the generation). About a 0% chance of that happening.
Looks cool, though
Looks cool, though
Steam only has something like 140 million monthly active users, so moving that much hardware is incredibly far fetched.
Console generations change every decade or so and the previous console gets abandoned. Anyone who buys a Steam Machine will continue to have access to the largest collection of video games in human history. Not to mention there are emulators for every classic console already and even the Nintendo Switch has at least two great emulators for it.
The PS5 is already about five years old, has had a slim release and a PS5 Pro. The PS6 announcement is probably a year away, with a 2027 or 2028 release.
Valve is launching a last-gen console, probably at a price that won't be competitive, right before the PS6 comes out.
Where does that leave e.g. Nintendo Wii, which is generally considered to be the same generation as the Xbox 360 or PS3, despite having not nearly the performance.