For me the Steam Deck is a shot in the arm to PC gaming and bringing me back to it to play games in my back catalog. Plus the Steam Deck runs Linux so you can do whatever else with it you want. Want to play Nintendo games you've already bought from Nintendo 5 times already? They will run. Want to play those free games you got on the Epic Games Store? Most will run. Want to play your incredible Steam back catalog? Most will work too.
Since the Steam Deck is running Linux and using Proton as the Wine emulation layer I expected things to be janky and I'm surprised it's as seamless as it is. I've been a Linux Desktop user and gamer for years and nothing in the past is this easy to use. Valve has done a ton of work and them owning all the hardware, drivers and Proton stack really adds up to a magical device that just works. Now all Steam games don't work, but I don't care much about that because I have thousands of games I'll never get around to playing anyway.
I got the official Steam Deck Dock and that works great on my TV and am currently replaying Borderlands that way. Bouncing between the Deck and my TV is seamless and occasionally there are issues, but it's nothing game breaking. The Steam Deck is so great I'll most likely purchase most new games digitally on PC because this really seems like the best way to play games.