How good do you think the Switch's year was in terms of 1st party game output?

IMO, I think this year was somewhat underwhelming, the only Major new 1st party game release we got this year was Animal Crossing and Nintendo pretty much left that game to carry the rest of the year, felt similar to 2018 where Nintendo wanted Smash to do the heavy carrying for a weaker 2018. 2020 was better than 2018 imo. However, I would still expect a little more in terms of new major games this year, which I can't really blame Nintendo so much since the pandemic definitely slowed them down this year.

-This year we got Animal Crossing which became a global phenomenon and made Switch sales soar, which is definitely a major game for a ton of people and sold like crazy. However, me personally I don't care about Animal Crossing and it isn't really my cup of tea, so I was left dealing with a long drought without major game releases for the 1st half of 2020. I'll still give Nintendo points for Animal Crossing tho cause objectively speaking it is a major game for most people.

-We also got Xenoblade remaster, which is an excellent game. However, Xenoblade doesn't really interest me or most people either as it is primarily a niche title that sells around 2 Million at best, plus its a remaster of an old game so it shouldn't really be considered a major game like that.

-51 Clubhouse Games is simple and cool, but again its far from major and really felt like a filler title.

-While I personally love the Paper Mario series and imo I do consider Origami King a major title for me that I did enjoy. I agree Paper Mario never been an extremely popular franchise usually selling less than 5 Million each entry, so objectively speaking I wouldn't consider it major.

-3D All Stars you could argue is major, but then again they're just HD ports of older games so I'll let you to decide if it's major. For me personally I guess it's big since my favorite franchise of all time is 3D Mario, but idk...

-Pikmin 3 DX, isn't major

-and having Age of Calamity as a holiday title just doesn't seem right to me, this is all subjective but a spin-off sort of Zelda game isn't really a holiday caliber title tbh.

So all in all, I 'll give this year a C.

Really poor.

My Ranking For Switch's game output by year:
1.2017
2.2019
3.2020
4.2018

I give it a C-. This year was too slow and way too dependent on old games (Besides the ones the OP mentioned, there was also Pokemon Mystery Dungeon DX and Tokyo Mirage), I actually think it beats 2018 as Switch's worst year so far. At the same time, I have to give it credit where is due. Animal Crossing NH was huge, AoC could easily become the best (And best selling) Warriors game ever, the third party releases was super solid this year and Xenoblade Chronicles DE is such an incredible remake of an incredible game.

At least Nintendo, like everyone honestly, have an excuse of WHY 2020 was slow,I have hopes 2021 will compensate this year.

EDIT: Also forgot to mention Clubhouse 51, it was a surprisingly good casual game from a franchise I honestly thought we would never see it back.

A for Age of Calamity.. for me it was A big huge surprise and this Mosu Game will be the best Selling Warriors Game ever.

I flirted with an F but seeing how they brought over Tokyo Mirage Sessions, something I was begging for, and a remake of Xenoblade plus brought back the Bionis Shoulder Map.That alone gives it a passing grade to me. Hyrule Warriors is next month. So I give it a C. 2019 was just so fucking ace and A++++ that 2020 feels pretty shitty comparison until you look a little deeper. It's nowhere near 2019 but it's not 2005 Gamecube either. Better than 2008 Wii which was a drought year for it.

That'll be the first time where we will witness a full third party support year with no first party effort on a Nintendo system.
Everyone made efforts for the switch for both 2020 and 2021 (so far) except Nintendo themselves.
And i can't allow myself to consider any of those lazy ports that were highly acclaimed any close from being proper games.
And yeah, let's not forget that Nintendo dared to sell 3 internally emulated roms at full price and called it fair enough for its N°1 selling franchise's anniversary.
to summ it up, one word can describe Nintendo this year (and likely the next one also): LAZY.

I used to be very critical of ports/remasters/remakes, and I still kind of am. I think it's lame to fill out a year with so much of that kind of content when your entire business model is essentially to rely on your own original content to sell your consoles. 

At the same time, I'm not going to lie, Xenoblade HD is now one of my favorite games of all time, and Origami King is one of my favorite Switch games. Both games that lived up to the relatively little hype I gave them, and both new games to me (well Origami King is new to everyone ... but, you know). And what little I played of the Pikmin 3 Deluxe demo was quite great, and I'm sure at least one of the three Mario games in the 3D All-Stars collection will live up to it's fame. 

So that's 2 remasters and a port collection, plus a brand new great game. And I don't know about Age of Calamity. Animal Crossing was alright. To me, that's better than 2017, where I only felt like Breath of the Wild lived up to it's hype. Then again, that's assuming I don't get majorly disappointed with every Mario game and Pikmin 3, but even without those I'd probably give it to this year. 

If I like all/most of the games I've yet to play, I'd give this year a flat B. If I don't, I'd give it a C+. 

So either way: 

1. 2019

2. 2020

3. 2017

4. 2018 

C borderline D. I haven't touched my Switch in a long while. Nintendo is really lucky people are still buying their console in droves.

C only because they released GOTY AKA Animal Crossing New Horizons

Otherwise it would be F

Too many ports and remasters. Ports and remasters are F-rated no matter what for me  and the fact they are Wii U ports made them G-rated

Not that I don't enjoy ports and remasters, I play them quite a lot (half of my Swotch library is ports and remasters), but if I need to give a score then I will always rank a new game, even a shit one, over a port