I do this so much by accident in desktop mode on the Steamdeck with a Steam controller. I dunno why big picture mode is apparently bound to pressing the Steam button on the controller (not every time, just sometimes!), but why is it even bound to anything when I’ve just switched intentionally to desktop mode? Why would I switch away from gaming mode just to enable big picture? What’s the use case that they’re catering to here by making it so easy to accidentally be in this situation?
Anyhow, pretty amazing that this minor annoyance is almost the only thing to complain about with my Steamdeck experience. Best gaming console I’ve ever had.