> I assure you, most people cannot tell you the difference between bounded polymorphism, parametric polymorphism,

And yet most people know one of Java, C# and Typescript and know how to use generics with constraints. Meaning they know those concepts. Your arguing my point for me. Knowing those concepts clearly isn't sufficient.

There are three things being discussed that you are conflating. Knowing a concept, knowing it's terminology and knowing how to all of them combine when used in a new concept. Knowing the underlying concepts does not imply the first. And similarly not knowing the terminology does not imply someone does not know the concepts as you seem to think it does.