For me, it will be a very tall order for any year to top 2017; the one-two punch of BOTW and Mario Odyssey alone, one of the best games ever made and one of the top ten of the decade, is colossal on its own, but add in Splatoon 2, Xenoblade 2, and Doom 2016, and it's truly fearsome. 2019 may have had more good games in total but for me it didn't offer any in the same godly league as BOTW or Odyssey.
breath of the wild is also on wiiU, was nothing new to the switch, splatoon 2 is mostly for online, I hated it, one of the worse games I played in the last 30 years, controls were also weird compared to most first person shooters. Single player campaign was too short and just bad.
Doom looks and plays much better on PC, xbox X and PS4 pro, by far, and its also way cheaper on those consoles, like 6 times cheaper.
Mario was OK, but not as good as many other 3d marios, it was far too easy, you couldn't even lose a life, and far too many collectibles. Mario 64 and sunshine and 3D world were better for me.
Xenoblade 2 was fantastic, one of the best rpgs of the last 10 years. All in all 2017 was disappointing for me on the switch compared to when I bought my N64, gamecube and wiiU.