I do think recursion schemes are pretty cool, particularly the idea that a list fold could be generalized to the concept of catamorphisms, which could be mechanically derived upon defining a data structure, because the shape of the recursion that's defined is the same as the shape of the recursion of the data constructors. It makes me realize that programming languages still could be higher-level; what if a programming language automatically derived the equivalent of the "fold" and "map" functions for any recursive data type defined by the programmer?

At the same time, the way it's implemented in Haskell's recursion-schemes library might be hard to wrap one's head around at first, kind of like how the list functions "foldr" and "foldl" are also often confusing to newbies, even though they're like the go-to, default way to make list functions in Haskell.