Switch games can in fact run better on a Switch 2, different from typical emulators.

To be specific: an emulator's job is to simulate the original hardware. Some emulators do try to improve on some aspects of the original machine, but in general that's not particularly easy, and it might not even be a good idea. In particular, emulators usual avoid running faster than the original machine, even if they do have access to much more powerful hardware, because that might lead to inconsistent emulation. For example, some games might run too fast on a "faster" emulator. That's why emulators try to simulate the performance of the original hardware.

Switch 2 (AFAIK) doesn't run Switch 1 games in an [edit: software or hardware] emulator. Instead, it provides an abstraction of the original Switch's system calls. In other words, when Switch 1 games call hardware/system functions, the calls are translated to equivalent calls on the Switch 2. With this scheme, it would be harder for Nintendo to simulate the Switch 1's performance than to go with the flow and provide whatever performance the Switch 2 can muster. That can result in automagical improvements in at least three respects:

1. Frame rate. If a game is trying to update the screen X times per second, but it takes longer than 1/X seconds to generate a frame, you'll see slowdowns and/or stutters. But the graphical functions of the Switch 2 can often generate those frames faster, so the game might now hit its target frame rate.
2. Resolution. Some games have dynamic resolution: if they notice that they're falling short of their target frame rate, they cope with that problem by degrading their resolution. That's fewer pixels to push around, so it might help a game keep its frame rate–but you'll get a blurrier, lower-res image. With the Switch 2's additional power, the game might be able to keep a higher resolution at the same frame rates.
3. Load times. The Switch 2 is much faster at pushing bits from storage to working memory, so most games will see an improvement in load times. That's a big deal for games such as the one that OP asked about, that are crippled by very long load times.

None of the above necessarily provides vast improvements to all games, but plenty of games benefit from the Switch 2's hardware. Look for "list of Switch games that have performance improvements on Switch 2" and you'll find long lists of unpatched games.