first: we too love package management systems. But there are several buts…
isn’t just a library or set of libraries which can be copy deployed. We need to have drivers (e.g. filter driver for GigE Vision) and services installed which require admin rights to install. And also as you guessed we depend on a licensing setup which needs services.
So we could create a NuGet package just containing the .Net wrapper DLLs. But these would only work with an installed version of with a certain minimum version. Thus your expectation of just installing the NuGet package to get a working app would result in a runtime error.
Because of that and to avoid confusion we bundle the .Net wrappers with our setup and install them to the GAC.
I hope that helps although it is not the outcome you (and I) would wish for.