
Valve continues to push Steam Input and Steam Deck to encourage more gamepad use on PCs. Last week, they announced some milestones related to this, mainly that 15% of all Steam sessions now use a controller and 10% use Steam Decks. These statistics are available in an official Steam News post.
Controller usage has tripled since 2018 (used to be at 5%); 42% of those controller sessions use Valve's Steam Input layer, and Xbox controllers make up 59% of those controller sessions, making them the most popular controller on Steam. Xbox is the leader of the pack in PC controllers, which makes sense considering how long XInput has been standardized. While support for other vendors has improved significantly in newer titles (esp. PlayStation ports), most games assume you use Xbox layout if you're on a controller.