> Abstraction is not beneficial when you need to study it later to understand it again.

This is where a good study routine comes in. I study Haskell like I study all things of any long term importance, using an Anki deck. It takes me longer to start using a new abstraction, but once I have it it's pretty much there for life, due to my daily commitment of half an hour or so to my reviews. It makes far less sense, of course, to do this for a one-off abstraction I had to apply to a specific project, so this naturally tilted me over the years to work more and more in loss like Haskell.

(N.B., I do not state this as a prescription. I think this is well above and beyond what most people expect of themselves professionally, and that is okay. Everything in life comes with tradeoffs.)