Detecting that the game runs on an emulator should be rather trivial I imagine.

In theory, it's also rather trivial to remove these checks from the game binaries (if you have the knowledge, but enough people have).

What Denuvo does is it not only implements these checks very effectively, but it also modifies/obfuscates/encrypts the game binary/code in a lot of ways. I honestly don't know a lot about how it works, but this deep integration makes it very hard to remove.

There are two ways you'd circumvent Denuvo DRM. Either by emulating all checks and whatever Denuvo wants in order to verify the game copy is "legit", or to completely remove Denuvo from the game binary. Both have proven to be very hard and a lot of work. There are likely only very few people out there with the expertise to do it, and of these people, most of them probably work for Denuvo (most people understandably prefer getting money for what they are doing as opposed to street cred), and most others don't bother.

There's one known cracker who calls herself "EMPRESS", but even she doesn't crack nowhere near all Denuvo games, as it's simply too time consuming.

Some people assume that the Switch version of Denuvo will be less powerful, but I honestly doubt it's that much less effective. I don't think Denuvo would announce Switch availability if they'd think it wouldn't be effective, they have a lot of high-paying customers to lose (or not to gain).

It's always a battle between DRM companies and the cracking scene, but with Denuvo it has been a steep uphill battle so far.