> having so many extra pixels lit as you read things

Your brain is excellent at turning words, even long ones, into instantly recognizable shapes. That's why transposing lteters as I'm doign in this sentnce doesn't harm readability very much.

Good, easily-maintained code is not poetry, and it's not math. It's Hemingway: short, terse sentences that say only what they need to say and nothing more. They are self-contained and self-evident.

On a semi-related note, there's a study showing that non-programmers have a much easier time reading code with more white space. To adapt your example above:

  var newCustomers = getNewCustomers()
  
  foreach(var newCustomer in newCustomers)
  {
     newCustomer.this .that etc.
  }

It's much easier for your brain to pull out different symbols when there's more white space.