String is a type alias for a lazy linked list of characters: not very high performance, but easy to work with using all the basic list manipulation tools.

Text is a compact and efficient representation, more similar to strings in other languages.

As far as learning libraries: its not mandatory and you can code as well as anywhere else without them, but the "language enhancing libraries" are undeniably useful, and can do some incredibly useful things. Monad transformers let you merge computational contexts, Conduit lets you cleanly define stream transformations, Lens lets you manipulate specific aspects of some state in a context, etc.

I feel your pain. Haskell makes it possible to write very powerful libraries which change how you think about your program, like MTL or conduits, and has APIs like Data.Text which change how you think about string processing. However, the language and community is quite mature.

Most of the debates either have answers (use Text instead of String, most of the time) or don't matter to most people (MTL vs transformers or monadLib). In my mind, it's no worse than trying to pick a JavaScript framework. If you're interested, give it a shot some day.

Except for Lens, most packages shy away from operator soup. The basic set you need to know to read most Haskell code is quite small, and tied to the core concepts you need to know anyway, such as:

    Functor (<$>)
    Applicative (<*>, <*, *>)
    Monad (>>=, =<<, >=>, <=<)
    Monoid (<>)
    Alternative (<|>)