Wii Sports Resort was bundled with the motion plus accessory and later would be bundled with the consoles as well. So it was still a similar concept.  

I agree with all the games mentioned but i feel DKTF port should get a mention, as i feel that underperformed also.

You’re acting as if Mario Maker is a replacement to 2D Mario when it’s not and is only a sales disappointment if you treat it as such. Fan made levels will never replace a full game made by Nintendo. It sold better than every Mario spin-off other than Kart & Party.

To be fair, it feels like Nintendo sees Mario Maker as a replacement to 2D Mario at this point.

Honestly its really difficult to find games on Switch that underperformed cause it seems like most 1st party Switch games end us selling record numbers for their respective francises. However, there are a few games I feel like underperformed and fell below expectations.

Like you said, Super Mario Maker 2 definitely underperformed in my eyes, 8 Million sold certainly isn't bad by any means, but considering how the Wii U version sold 4 Million (Around 1/2 of MM2 Sales) with an install base that 9 times smaller than the Switch with most Nintendo games heavily exceeding expectations with sales on Switch. 8 Million is far less than what I expected. I felt like Mario Maker was bound to become one of the biggest games on Switch with the potential of selling 20M+ cause consumers love 2D Mario games as shown by the 30M+ sales of some of the NSMB games and I thought people would go crazy for essentially an unlimited 2D Mario game with a ton of variety and new ideas compared to the staleness we were seeing in the NSMB series at the time, along with the ton of content in MM2 with story mode, different art-styles, and the ability to make your own entire Mario game with a hub world. I thought it'll be the perfect type of streaming game to where word about the game could spread through live streams alone, as it sort of reminds me of Happy Wheels when it was big. It was super surprising to see the port of NSMBU with far less ambition outsell MM2 by twice as much.
However, I could sort of see why consumers might be turned off by Mario Maker 2, they didn't like the idea of making their own levels and didn't like the idea of playing levels from other people outside of Nintendo since they probably get scared by the fact that the levels might be garbage and not offer the simple fun experience of NSMB. I could also relate to this a little cause it is a little annoying to scour for good levels in MM2 and find simple levels and that probably turned people off. It's a shame though that it underperformed however cause Nintendo really was ambitious with the game adding a ton of ideas as it's really hard to name any content that was missing in MM2, Nintendo added all the necessary content and added way more which made the game so awesome, but it seems like people prefer the simplicity of NSMB.

Another game that underperformed in my eyes is Zelda Skyward Sword HD, again 4M isn't bad but I was thinking it would've sold maybe close to 10M cause I felt like the immense popularity and success of Zelda BOTW would create a ton of new Zelda fans who'd be interested in trying out the previous Zelda games as it seemed like Zelda BOTW fans were thirsty for anything related to Zelda after BOTW. However, that wasn't the case for Skyward Sword which sold around 4M. I guess that the majority of Zelda BOTW fans are primarily interested in the more open world more western RPG type Zelda games like BOTW and aren't really interested in the more linear Zelda games. The 60$ price tag of course was definitely overpriced for 1 10 year old remaster that was priced at 50$ when released in 2011 which may have contributed somewhat, but I think its moreso the fact that linear Zelda games appeal to a more niche audience that BOTW.

I'll also say that Paper Mario Origami King underperformed as well. I was pretty certain it would end up becoming the bestselling paper Mario game in the franchise considering that it was on Switch, the console where most 1st party franchises reach record sales, and that Origami King was reviewed mostly positively and was considered better than the more recent PM games. However, Origami King failed to become the bestselling game in the franchise selling around 3.43M and sales dropping off a cliff after the launch period, while Super Paper Mario sold 4.3M on the Wii. I guess SPM outsold origami king cause SPM had elements that made it look sort of like a 2D Mario game which may have appealed to a larger audience.

For Mario Maker 2 I wonder if a significant factor is some people thinking making levels is mandatory/all there is to it.

I kinda fear the end result but I'll say this compared to its predecessor, I kinda feel like Xenoblade Chronicles 3 sales will being slightly disappointing from what I personally expected when it launched.

Time will tell if the standalone story can give it a needed second wind, but I really wanted this game to be the moment where the franchise breaks the shackle and gets just as popular as Persona for example.

Guess it'll need more time in the oven before it happens but, it's slowly getting there.

I think for being more expensive than the Wii U version 4mil is pretty good.

My bad, I didn't know that

If you're talking about Super Mario Maker 2, don't forget that this game was pretty much unfinished at launch and the most important things were missing: online multiplayer mode, super world editor, play levels made by Switch friends etc. Compared to Mario Maker 1 on Wii U you have worse controls with controller and touchscreen and almost nothing to unlock. Even worse: you can lose the medals you've earned.
Compare that to Mario Maker 1, which had the 100 Mario Challenge to unlock new characters you can play with - and you got new items for the editor every two weeks. The whole Mario Maker 2 game was a mess. A rushed release without a concrete plan. It also didn't help that Nintendo stopped supporting the game within less than 1 year.

OP:
Sales of Labo were disappointing. ARMS and 1-2-Switch were not the big new hits, which Nintendo maybe had expected. Yoshi's Crafted World, Astral Chain, Captain Toad, Miitopia, Mario + Rabbids Sparks of Hope also underperformed.