Using map, fold etc. is not the hard part of functional programming. The hard part is managing effects (via monads, monad transformers, or effects). Trying to convert a procedural inner mutating algorithm to say Haskell is challenging.
There used to be a YouTube subscription called Premium Lite which was just ad-free YouTube. I happily paid for that until they shut it down and tried to force the much bigger
subscription on me (nothing else in premium is relevant to me).
Now I use smarttube which is not only ad-free but also has tons of nice features which YouTube will never deliver. However, should premium lite comeback I would pay for it but keep using smarttube.