This article includes sales estimates for different handhelds from market research firm IDC.
They place total handheld PC sales of the Steam Deck, RoG Ally, Lenovo Legion Go, and MSI Claw at almost 6 million units for the past 3 years. It’s estimated that the Steam Deck makes up between 3.7 to 4 million of those sales, more than all the other major handheld PC manufacturers combined.
Honestly the Steam Deck could never become more powerful and I would be perfectly fine with it. Hardware reliability, ecosystem maturity and quality of life features are what actually matters. The deck already can run several lifetimes of indy games and that is just going to grow.
Chasing performance to improve Steam Deck sales I think is a subpar play, though that being said more powerful hardware is always welcome.
Honestly the pc gaming market (excluding indies) has an irrational obsession on focusing only on making performance heavy games with extremely taxing system requirements, the Steam Deck blowing up in popularity with its subpar hardware is honestly one of the best things that could happen to the pc gaming industry.