Saving 20% of your income is way beyond emergency funds and what is needed for retirement. Typical guidelines for emergency funds are to set aside at least 6 months worth of living expenses, you don't need to save 20% forever. If you saved even 10-15% of your income for retirement your entire life, you'd have a very comfortable retirement (assuming the world doesn't burn down before then).
SmartAsset is a financial advisor service, and these numbers seem to be guidelines for middle-class earners. That's pretty far beyond a minimum cost of living, so I'd say this title is misleading at best.