Let’s now take a look at static members of a class. Again, a static object is one that persists in the memory the entire time the application is in execution.

To facilitate that, I need a TypeScript object to use on the client that has identical properties to my C# object. I can't reuse C# objects in TypeScript, of course, but it would be great if I could ...

I won't say that, all by itself, C# 9 is worth the migration to .NET 5 (I might make that claim about C# 8 and .NET Core 3.x, though). The new version of C# 9 is more than just a nice feature of .NET ...