Uber/lyft are also slaying yellow/black cabs because the cabs chose to just milk their monopoly for maximum profit for 30 years rather than invest in any technology or make any improvements to rider experience or comfort. It's not just the subsidies. It's the fact that calling random 800 numbers trying to get a cab is really frustrating, especially when they do not show up 20% of the time.

For Amazon... are their margins really that much smaller than Walmart, Target, Costco or anything other big box discount retailer? Many products at Amazon can be found cheaper in a store. It's just really damn convenient to order it on Amazon and have it shipped the next day.