Maine’s own Stephen King testified last week in a federal antitrust trial. It was scary stuff.

King was the government’s star witness in its case against the merger of Penguin Random House and Simon & Schuster, two of the country’s biggest book publishers.

Allowing the merger between the two giants, which together accounted for nearly half of the top 100 print books last year, would reduce competition, making it harder for authors and smaller publishers to make their way in the industry, King testified. It would stifle creativity and keep new voices from being heard, he said.

He’s right. And the scary part is, he could have been talking about any number of industries where corporate consolidation has hurt workers and kept new ideas and practices from seeing the light of day.

King has seen the change in his industry firsthand. He published his first book, “Carrie,” on Doubleday, which merged with Knopf Publishing Group in 2009 and is now a part of Penguin.

The consolidation has given the publishing houses more power, cutting down competition when they go to sign authors. It has also elbowed out anything that can’t bring in a large profit, with the publishers relying on brand-name authors, celebrities and public figures to the detriment of new authors, journalists, poets, historians and others who don’t command huge audiences.

So while the merger may benefit established writers such as himself, King said, the industry as a whole will become less varied, less interesting – and profitable only for a select few.

“The more the big publishers consolidate, the harder it is for indie publishers to survive,” King told The New York Times last year. “And that is where the good writers are currently starting out and learning their chops.”

It’s not just publishing. In industry after industry, fewer companies hold bigger pieces of the pie. More often than not, they use that power only to accumulate more power and profits – hurting workers and consumers.

The meatpacking industry, for one, is now dominated by just a few firms who have gained so much power that they are able to force farmers to pay lower prices while raking in huge profits themselves. They also hold too much sway over regulations, leading to lax oversight of labor and food safety violations.

That’s not all. Hospitals, agriculture, broadband and cable providers, airlines, manufacturers of all kinds – they’ve all come under the control of fewer hands, in fewer places, through the last few decades, most often at a direct cost to the communities who have lost out on investment as a result.

Nowhere is this more glaring than with Big Tech. Companies like Facebook and Google own so much of the internet that it is nearly impossible to use without handing them data, which they use to gain more revenue, which they use to buy or block out competitors, further reducing competition and innovation.

Amazon, too, has in highly suspect ways gained too much control over who gets to sell what online, allowing the company to write the rules in ways that benefit it and further allow the company to gain market share – again with consumers, workers and small sellers on the losing end.

That brings us back to books. The merger between Penguin and Simon & Schuster is a direct response to Amazon, which is the largest book seller in the U.S., giving it enormous leverage over publishers. If a publisher controlled enough titles, however, some of that power may shift back to them.

The idea is that it takes a monopoly to compete with a monopoly – a kind of corporate race to the top that usually leaves the rest of us at the bottom.

The Biden administration this year announced it is changing how the federal government approaches mergers, abandoning a pro-consolidation policy that has spanned multiple presidents in both parties.

Reversing the decades-long consolidation of power and market control won’t be easy, but it’s necessary.

Our current course, as Stephen King well knows, is a nightmare for everyone but a few companies and their shareholders.