They did try this a while back, steam machines were around at 2015. I could see it getting a rebirth in a similar design to the steam deck in a few years though.
Steam OS and big picture weren’t very mature yet at the time. I think now that the Deck has proven the UX, they could definitely revisit this idea. And I pray that they do because it could mean more Steam controllers on the market
Seriously, I ordered a steam controller right before they were discontinued, and got a refund :(