Haskell is actually very easy.
This is just my heuristic but Haskell has just 25 keywords. For comparison: C 32, Java 53, C++ 83 and C# 102. What makes Haskell confusing are the 115 GHC language extensions. Each is basically a new concept to learn. Every time i join a new and sufficiently large project, I stumble across an extension that I am not familiar with.
https://downloads.haskell.org/~ghc/latest/docs/html/users_gu...