Why does Google provide for free a tool without which it’s impossible to imagine contemporary life? Because it can monetize it with advertising. Without the advertising, which Warren insists should be a separate business, Google has no incentive to devote engineers to improving its search engine.

By the same token, no one will welcome iPhones that no longer come with or sell Apple apps. And would people really appreciate having to go to two different Amazons, one just a platform, one selling Amazon products?

This is all silly, as are the mergers that Warren pledges to reverse, including Amazon’s acquisition of Whole Foods. Amazon doesn’t have anything close to a monopoly in food retail. Rather than taking over the sector, it’s spurring investment and innovation. The nation’s largest supermarket chain, Kroger, was slated to increase its spending on investment 200 percent in 2018.