Check out “Dave the diver”. I’ve fallen out of love with gaming as well and I’ve been dropping a lot of hours into this game on my steam deck. Super unique and easy to pick up and put down. Feels fresh.
If you like platformers Bzzt just came out and would definitely run on the deck. For roguelikes I’d recommend Darkest Dungeon, Hades, or Rogue Legacy. For a straightforward RPG with 3D models but pixel art I’d recommend Octopath Traveller 2.
I also recommend Dave the Diver as well, fantastic game.