Seven years after launching the Steam machine (2014) initiative, there are no Steam machines available for sale. [1]
Both the Steam Controller (2015-2019) and Steam Link (2015-2018) are discontinued and cannot be purchased, despite consistently positive reviews from users. [2]
As other commenters have noted there are already numerous "Switch-like, but x86" products that exist, and it's unclear to me what innovation Valve can bring to the space.
IMHO if Valve wants to be taken seriously in the hardware market, they need to stop pulling a Google and actually support/iterate/not discontinue their existing hardware products (before someone adds that they did support these through firmware updates, I mean updating the hardware to keep up with the times, Steam Link with apps or 4K, etc).