The USA now evaluates monopolies based on just one thing: their ability to control and manipulate prices charged to to household customers. Using market power to raise prices to household customers, the way Enron did to California electricy users, is against public policy.

The anti-trust dismantling of the tech behemoths advocated by this author cannot happen unless public policy changes so it also discourages monopsonmies. https://en.wikipedia.org/wiki/Monopsony In other words, companies like Amazon and Walmart don't increase prices to their customers. Instead, they have power to decrease their payments to suppliers. But that's not against current US public policy.

Also, I wonder about the wisdom of using market cap as a measure of a business's size. That's a peculiarly sili-valley way of measuring things, and can be very inflated. Take Uber. It's a pirate (informal) cab company with an excellent app. It loses money every year. Most cab companies would run out of gas if they did that. But not Uber.

It may be better to measure company size by revenue or even, gasp, by size of payroll or by profit.

And, the word "firm," used by this author, is jargon from the academic field of economics. It's a tell about theoretical vs. real-world advice.