Are packages now cached in a more shared location somewhere or what?
My solution folder is devoid of any packages
folder:
You can check out a question I asked to see if the answers do you any good.
How do I include NuGet packages in my solution for .Net Core projects?
You can get that packages folder back, but you might not be happy with the results, since .Net Core projects rely on so many NuGet packages. Mine is hovering around 1 GB.
https://docs.microsoft.com/en-us/nuget/schema/nuget-config-file#config-section