It’s for enterprise SSO (used to be called Azure ActiveDirectory), so your workplace might use it for logging into internet/intranet apps for example.
The main reason I’m fine with it is that Nitrokey has always been kind of meh for a lot of people. I hear a lot of mixed reviews, and their business model has always basically been reselling products with minor modifications. I think we should just recommend SoloKey as an open-source FIDO2 key.