Why would oil companies not benefit from economies of scale? These aren't Bain-style leveraged buyouts.
It's true that once a company gets a lot of market power, either as a buyer or a seller, it causes problems. But by this logic, why not breakup Walmart first? There's lots of documentation on how they push supplier cost so low that suppliers are practically going out of business selling to WalMart. Google seems less problematic than lots of companies.
Across all retail in the US Amazon makes up 5%. Walmart makes up 15%. Shouldn't the burden of the question be reversed in light of this? While online retail is growing relative to brick and mortar it is either premature to call it "too big" in absolute terms when a largely brick and mortar competitor is triple the size and not a monopoly seems farcical gun-jumping until it exceeds a max non-monopoly. Whatever the legal standards they should be consistent.
Age of Amazon is just a narrative which is no way to decide monopoly.
"15% of total retail sales in Grocery, Home furnishings, Electronics, Apparel, Sporting goods, General merchandise and Office supplies"
That's not all of retail. It's certain categories in retail. It's significant, but Amazon has a much broader selection of products and competes in far more sectors of the retail industry than Walmart does. Also, looking forward, over the next 10-20 years and given the changes in the marketplace, who do you think is best poised to dominate retail for the foreseeable future: Walmart or Amazon?
Not really. My point is that every time someone brings up a reason to break up any given company that the same reason applies to many other companies equally well. People seem to be basing these calls on feelings and not on any underlying principle.
It's true that once a company gets a lot of market power, either as a buyer or a seller, it causes problems. But by this logic, why not breakup Walmart first? There's lots of documentation on how they push supplier cost so low that suppliers are practically going out of business selling to WalMart. Google seems less problematic than lots of companies.