I'm not a fan of digital only or a fan of Steam in general. You could use a steam deck as a GOG deck and only play DRM free games. You also won't get access to AAA games from big publishers without DRM but those games either don't come to switch or are heavily nerfed anyway.

To me thats missing the point of the thing being a a handheld console with SteamOS rather a PC. If you use it as a PC instead of a console it IS a pretty open ecosystem. But then it loses its main advantage over a normal PC or the other handhelds in the market which is its tight integration with SteamOS and the ability to be a handheld PC gaming console. It does keep its secondary advantage of price though. The Steam Deck is a good piece of hardware but I don't prefer its form factor for what I see as its niche as a Switch competitor.

On the contrast, the switch is made to play switch games and I'm able to play any physical cart on any switch with a working cartridge reader without ever connecting the system online. That's the advantage the Switch has over the Steam Deck when it comes to games and DRM