Short answer: because it just came out this month.

Slightly longer answer, there are 78 new games confirmed for Switch 2 - 89 if you include Switch 2 Editions that function as updates to existing Switch 1 games. That's not a small number for a console that just launched: https://en.wikipedia.org/wiki/List_of_Nintendo_Switch_2_games

As time goes forward, so too will the games announced. Nintendo and partners usually only announce a small number of titles more than a few weeks in advance of the release date.

1. It just came out.
2. Even with Nintendo's successes over time and Switch 2's record launch, Nintendo is often more a pain for third-party developers and publishers than PlayStation and Xbox. And part of that is the ceiling for the specs. Switch 2 is still weaker than a Series X and PS5 as we know it would be.
3. A lot of digital-only releases get short windows of confirmation. Switch 2 is looking to have fewer physical third-party games than Switch.

They're coming.  

Seems ironically western publishers are doing much better job than Japanese publishers when it comes to Switch 2 support. Japanese publishers for some reason are going all in on PC/Xbox/PS no matter how many records Nintendo consoles break.

I demand that we change this thread title to, "THE SWITCH 2 HAS NO GAEMZ AND WE NEED TO TALK ABOUT IT!!!"

If you know, you know

Third party games typically sell bad on the Switch.