What do you mean?

These concepts are usually explained via first-principles definitions, and they are usually opaque and unapproachable for most people. That's not a coincidence.

There's nothing in this list: - Algebra: Semigroups, Monoids. - Algebraic Data Types: product and sum types. - Functor, Applicative, Monad

which covers basically all the fundamentals to be proficient in functional programming that has definitions that are opaque and unapproachable. And all of those have very simple examples, both in real life and especially programming. But definition has to come first, or you have this great mass of people that do not understand what they talking about even when they blog about it.

If you can take your time to understand that a type constructor (and take the time to see what it is) and a map function form a pair called functor, you are equipped to learn about monads.

It's not rocket science, but yes, it requires a bit of studying and learning, which is what people don't want to hear, and instead choose the long road of contrived example-driven, inaccurate and confusing blog posts.

As another commenter pointed out, the key is to use an example as a starting point and then refine from there. "X is like Y, but different in these ways". Comparisons don't muddy the waters; they give people a quantum-leap from 0% understanding to 70% or 90% understanding, from which point the remaining gap can be filled in at the usual rate. To ignore this is to ignore human nature.