If you have an array and an index, you have all the complexity of pointers. The only difference is that Haskell will bounds check every array access, which is also a debug option for pointer deref.
Hard to believe that “learners ... get confused over mutability” more than functional programming when millions of middle-schoolers grokked the idea of “mutability” in the form of variables in Basic, while I (and at a guess, at least thousands of other experienced programmers) have no fucking idea about pretty much all the stuff in most of the tens or hundreds of articles and discussions like this that we've seen over the years. Just plain stating that “mutability is more difficult” without a shred of evidence ain't gonna fly.