I dont know their needs, but last time I tried to do a computer-vision project on C#, all libraries in Nugets where shitty wrappers for cloud solutions or just paid libraries (last update to OpenCV is 7 years old).

Using bindings to C++ libraries is likely to yield better experience. C# has really good interop API (P/Invoke).

I don't have experience with machine vision but here's an example of a speech2text library that integrates whisper.cpp in an idiomatic way: https://github.com/sandrohanea/whisper.net

There are many good community projects with code quality way higher than your average enterprise SDK with layers upon layers of abstractions and allocations. Finding them is the same as with most other languages like Rust or TS.