I also never used my dock much, until I started playing Xenoblade Chronicles 2 and more recently Hyrule Warriors. While both games are entirely playable on handheld they do suffer from some visual/performance issues. Hyrule Warriors runs at a supersampled 1080P in handheld which causes the game to have very choppy framerate, I don’t usually notice framerates but in this game it is immediately apparent that it runs way better in docked mode. With Xenoblade it’s more of a resolution problem as the game uses a dynamic resolution in handheld mode and sometimes it looks really blurry. Neither of these issues are deal breakers mind you, but they do exist.
One other thing I thought of now. Pokemon Let’s Go supports two player, but only in docked mode. I play with both joycons at the same time myself to make catching Pokemon or battling trainers easier. It’s also great to be able to dock the Switch and hand a joycon to my nephew to join me in Mario Kart or Hyrule Warriors or whatever else.
Yeah I have a PS4 that’s connected to my TV, but my PS4 can’t play Switch exclusives.
It’s probably not a big deal but the HD rumble is awesome. Of course if it’s not there it won’t really bother you, but it is great to feel it. Motion controls are a bit of a hit and miss. Games like Doom or Warframe play really well with the gyro controls and motion aiming works well in Zelda BotW as well, but other than that I don’t really use it either.