Something to consider with Switch 2 and general attitude of third parties towards Nintendo platforms is the difficulty of competing against Nintendo's first party titles. Whether or not it's a warranted idea, third parties see Nintendo platforms as a place where Nintendo succeeds first, and others pick up the scraps, especially if you're not working directly with them with a publishing deal or exclusive marketing deal.
The entire problem for 3rd parties and Nintendo consoles since the Wii: is that Nintendo hardware has been a lot less powerful than Playstation/Xbox/PC.
Often, a game made with Playstation and Xbox in mind, can't scale down well enough to be a good experience representative of (insert game here) on Switch.
So then you either have to budget an entirely original game dedicated to Nintendo's hardware. Or.....skip Nintendo.
And making a dedicated game can be an even larger endeavor than one might think.
1. if you make the game part of an existing IP-----well then you have to wrangle with cannon, continuity, etc. And balancing that can either water down a game and/or alienate the main fanbase on other platforms. Its tricky.
2. making a whole new I.P.: Well we all know how tricky that can be. And to bother to do it while targeting one platform, its probably seen as relatively more risky. Sure, you can port other platforms. But the visuals won't be equivalent to the hardware on other platforms, which can affect sales.
3. Having to make a bespoke game for Nintendo hardware has almost always meant less overall budget. When's the last time you played a truly classic feeling CoD on a Nintendo console? They get the short end of the budget.
Nintendo has really strong IP. But, part of that is because they are able to focus all of their money and talent, into single versions of their games. So the games usually end up being technically sound, if not very good games within their genres.
Also, as a first party, their games are more deeply seeded to the arch of the total brand. And they can risk more on longer R&D for novel techniques, as well as longer bug and quality testing.
And in the end, if the next Mario sells poorly, Nintendo isn't going to shut its doors. Whereas a lot of developers live game to game. Or might be able to weather one game selling poorly. But then need a big success on the follow up, or it could end them.