> If you're writing 3 business rules in something that's important and needs reliability and therefore should not have complexity ? Then it might be better to write it out.

I'd give you multiple upvotes if I could for this.

Absolutely agree with all your points.

I'd add further, that if it's 3 important business rules, then sometimes expanding it further to have well-named functions and well-named variables is well worth doing, even if the business rules are trivial logic:

  // This rule was recommended by the accountant on 2019-05-06
  // and must be reviewed by the CFO before release.
  function receipt_needs_itemised_tax_record(amount: Money): bool {
      return amount >= 1.00;
  }

  // Show itemised tax records on receipts that need it.
  if (receipt_needs_itemised_tax_record(receipt.total_paid)) {
      ...
  }

Versus:

  // Writing this and other low-level code in 25 lines per function
  // does not make the 10kloc rendering library easier to understand.
   function transform_pixel(bg: RGB, fg: RGB, opacity): RGB {
      opacity = clamp(opacity, 0.0, 1.0);
      let blend_bg = 1.0 - opacity, blend_fg = opacity;
      return RGB { r: clamp_rgb(bg.r * blend_bg + fg.r * blend_fg),
                   g: clamp_rgb(bg.g * blend_bg + fg.g * blend_fg),
                   b: clamp_rgb(bg.b * blend_bg + fg.b * blend_fg) };
  }