Sure. By default you get the Steam store. Correct me if I’m wrong, but it’s the only option to load games from the default Gaming interface. There is no option to load from Gog, Epic, Uplay, Playstation, Xbox, Nintendo, or any other 3rd party store. If you are not willing (or able) to manage the deck in desktop mode, you can’t install non-Steam games so - as a console - it’s a walled garden. I say semi- because it’s not terribly difficult to switch to desktop mode and install other applications, launchers, and games - but if you’ve never used Linux and are not computer savvy, Steam is the only way to get games onto the device.