Honestly unless  remakes  are like resident evil 4 remake, it doesn't interest me. It's a game that i experienced before with out dated gameplay and a shiny new paint.  

Not saying it's a bad game but I fell out with ToTK after a few hours. Just 2019 had way way way more and all excellent games. I need more and more variety than just Nintendo Wells of the same old franchises.

2019 of course. Yoshi's Crafted World, Mario Maker 2, Link's Awakening, Dragon Quest XI and Luigi's Mansion 3.

Though, I think 2017 is the best Switch year overall and the best launch year ever for any console.

2021 has my personal holy trinity: NEO: TWEWY, Metroid Dread and Shin Megami Tensei V, so that's my year. But objectively speaking, nothing beats 2022. The list is above me. It's not only Switch's best year, it's probably one of the best years for any platform. Period.

2023. By a lot! I've always wanted to see a 2d Mario and Zelda in the same year. I feel like I am dreaming sometimes. So happy!!

To be frank, whatever if 2017,2019,2021,2022 or 2023 fit your tastes more. I just think it's amazing the amount of consistency Nintendo finally had with it's software pipeline this generation.
Not many publishers could vent themselves for having multiple years in a row of good content.

2019 > 2017

Edit: I also realize the level of enjoyment depends on whether or not Switch is your only system, because Switch library have lots of ports

For example, Metroid Prime on Switch for me is great because playing it legally is not easy, plus a remastered version is very welcomed 

In other hand if you have a Playstation Persona and Nier late releases will hardly hype you unless you haven't bought they on Playstation for some reason. That's why 2021 and 2022 were a bit barren for me, I have bought 2-3 games a year and gamed mainly on Playstation 

2023 is surprisingly the best for me, because it has many new games, not ports of other systems. Between Octopath, FE Engage, Zelda (all huge games with lots of value) I think I have already invested more time on Switch this year than 2021 or 2022. And I still have Pikmin 4 on sight and the already stated Metroid Prime. Switch will probably end the year as the system I used the most 

The sad side is the second half of the year is dedicated to Mario, and I only like 3D Mario :/, maybe I will give a chance to Mario RPG, I'm only reading good things about it 

I mean, it depends on what one personally values most, and for a lot of people, Zelda and Mario trump all else when it comes to what matters on a Nintendo console, as Nintendo's two flagship franchises.

Depending on how you feel about remasters, Prime and Super Mario RPG could also be great additions or meh.

Ooof...

Man, I REALLY had to think long and hard about this one. I even made a list of some of the Switch games that released in each year that I thought were noteworthy, and these were the ones I came up with:

If any of you guys have more suggestions, feel free to Quote and add on!

But based on this short list I put together... And lots, and I mean, LOTS of internal debating, I would have to go...

2022 > 2023* > 2017 > 2021 > 2019 > 2018 > 2020

*This is assuming none of the games listed under 2023 get delayed.

Totk bundle recent.  No one knows how long till switch succesor launches.  And the recent showcase of nintendo games coming, indicates it's atleast a year from now.