Daily Cuts - Why are we paying for standard seats on full-service airlines?

Paying for extra leg room and other so-called “special” seats on a flight is normal in today’s context, but full-service commercial airlines are charging even to select standard, no-frills seats. How did this quietly become a norm, and are the benefits to the airlines worth the customer complaints? Andrea Heng and Hairianto Diman get a better understanding from Aaron Wong, Founder, The Mile Lion