Yes! I can make some recommendations on some good accessories that really add to it when he gets it up and running. Highly recommend getting a USB-C hub that has HDMI output and Ethernet ports (
one I have) - that way if you EVER want to output to the TV and play like a console it'll be fully set up for it.
On the portable battery pack front (it WILL eat up power), get a USB-C compatible one for laptops. I got an 80W, 26,800 mAh one for whenever I travel with it.
Otherwise, the beauty of the device is JUST how turn on and play it is with most releases. If he's got a Steam library already, I'd recommend starting with the "Great on Deck" tab that the machine gives. Everything in there works wonderfully to start. Once you get a bit deeper in, there's some more customization you can do to make games that don't work immediately start working (I'd just google Proton-Experimental Steam Deck, there will be tutorials).