there can be multiple versions of .NET Core , .NET Framework is not so fortunate
>While there can be multiple versions of .NET Core on one computer, .NET Framework is not so fortunate, and Redmond knows it.
Unless things changed recently, different versions of .NET framework ARE very much separate for exactly this reason, that .NET can introduce breaking changes. Certainly when I was last working on .NET you'd commonly see different frameworks installed side by side. If you needed 2.0 then your 4.0 installation wouldn't (IIRC) work?