From the article--

let x = 'outer';

function test(inner) {

  if (inner) {

    let x = 'inner';

    return x;

  }

  return x; // gets result from line 1 as expected

}

test(false); // outer

test(true); // inner

This makes it seem like let creates global variables. Why would you want to return a variable from outside the function? Doesn't that create massive overhead in terms of keeping track where variables are initially set? Easy to understand in this example, but what if let x = 'outer'; is defined at the top of a 5000 line script and this function appears near the bottom?

Edit: Turns out I don't know how to format code. This is in the first example of section 3.1 Block Scope Variables.