I agree lazy file I/O can be dangerous and needs to vanish, but I'm not sure this counts as an "algorithmic" complaint, which is what I was really curious about.
I also don't think you need Conduit or Pipes or any other performance destroying free Monad libraries to deal with it. My hot take: Conduit is in fact awful and radically overused and multiple superior options exist.
I totally agree the prelude is full of cruft and needs to be scraped and redone fully. But the data structures libraries are all really good and if we could just pull in the succinct and unordered stuff, it's gone some of the best data structures a standard library can ask for.
I also don't think you need Conduit or Pipes or any other performance destroying free Monad libraries to deal with it. My hot take: Conduit is in fact awful and radically overused and multiple superior options exist.