To wax metaphorical, I'd rather the monsters devour each other while we race for a super-weapon to defeat all monsters and protect real people.
This situation where corporations are effectively replacing the state is not exactly what I had in mind when I said the world would be a better place with a diminished role of the State in individual life.
And I think it would be very difficult for a company to offer the level of convenience and good UX that Amazon does at a much smaller scale. For example, part of why they can get very fast shipping down to a reasonable price is their huge network of distribution centers + their size giving them leverage in negotiations with UPS/Fedex/et al.
If you split Amazon into a dozen smaller companies, the overall customer experience would likely be worse.