The development team I'm on at work, seems to detest using NuGet for anything. I've been working with them for 5+ years. They've always been this way, but in the last year or so they've become more adamant about not wanting to use NuGet for anything. Last Friday was one of the worse days I've had trying to encourage my coworkers to use NuGet. We were experiencing network issues, making it difficult at best, or impossible at worst, to reach the Internet. This colleague had been working on a project, which stopped building in our TFS 2015 build server. So, he asked me for help. There were various causes that were being revealed in the build server's logs. But before we could get into them my colleague just started gutting the project of all NuGet packages, replacing them all with some DLLs he got from some other Visual Studio project.
As an aside, this practice has been for longer than I've been there, their favored way of bringing some functionality into a project. They either know of another project that has a DLL that will do what is needed, or at least close to it. Either that or they go looking throughout all the TFS projects for a DLL that will do what they want. Then they'll get that DLL and copy it into the project they're working on, then go on from there. They do this over and over again, until God only knows where the DLL originally was, and no one knows how old it is.
I think that the issue, last Friday, was Internet connectivity. However, I couldn't show that, because I don't know what URL VS 2019 uses to bring in a NuGet package, or what VS 2015 (on the build server) uses to pull in a NuGet package. As an aside, I'd love to know what the URL is that VS 2015 or 2019 uses to bring in NuGet packages.
I suspect that their hatred of NuGet would extend to any package management solution, such as npm.
What I would like to know is what compelling reasons are there for using NuGet over just copying DLLs from one project to another ad nauseum?