> as of right now, you need to know category theory to understand the language and it's base libraries.

This is patently false. You need to know what a Functor and a Monad are, as typeclasses with attendant laws.

But you don't need to know the definition of a "Category" much less any actual CT.

There's nothing baked in. I think people just use "I need to learn CT" as an excuse for not learning things, to be honest.