The Valve Index is the least popular VR option and doesn’t rank near the top of VR headsets. Still being beat out by entry level Oculus.
The Steam controller was poorly made flop and has been discontinued. The vast majority of reviews put the controller well below the Xbox controller, which was already PC compatible.
Steam Deck is very expensive and has a very poor battery life. Making the handheld cable tethered. It also went against its open promise by including locked down proprietary software.
Steams customer support ranks the third worst of all top level game stores. Just above Ubisoft and Blizzard.
You mention their Linux support yet the majority of games are yet to be supported and plenty of game will never be supported due to their nature or inclusion of anti-cheat. The only thing Valve has done was release the Steam Client to Linux.
Steam popularized gambling for children and continue to be one of 2 PC companies that continue to do so.