Repairability and general hackability are core design goals of the Steam Deck compared to other devices. On the software side, they don't hide the desktop Linux core.
And then there is the incredible work done on Proton. I couldn't have imagined the future of gaming on linux was that Wine would be improved so much you couldn't tell it was being used.. At the time everyone figured you just had to complain in the game forums for a linux version and eventually it would work.