There might not BE a better company. In the system you describe we'd end up with even more strictly defined economic classes, because the wealthy would have the ability to collectively decide policy without interference. You'd just be creating an oligarchy.
The idea is there is no policy, just companies competing for customers and employees and giving them both the best value or the customers and employees would move on to a better company.
Why compete when you can destroy the other companies without restrictions?
Imagine Walmart buys the local water company then cuts water off to their competitors by charging them an exorbitant amount? Or the local power company? What's to stop them?
They can just absorb the local utilities and start intentionally giving their competitors terrible or no service and drive them out of business.
How would they get the capital together (a massive undertaking) or the equipment together (again a massive undertaking) as Walmart buys up the entire supply chain to provide the pipes and power lines?
Oh you want to hire an electrician for grid work? Walmart won't sell you or rent you the equipment. Want to hire a plumber for grid work? Walmart won't sell you the required equipment to set it up.
Not even that but what's to stop them from corporate espionage? Sabotaging their competitors. "Oh we trap rain water and truck it to people. Lately people have been getting really sick from our water but not Walmarts water."
But their only customer would be the one store Walmart is shutting down. Why would you lay millions of dollars of pipes and more millions of dollars in purification infrastructure just for one money strapped store?
The established supplier would just buy the new competitor. If they don't sell, the established supplier would pricedump and eat the loss, since they're already estabished, until the new competitor agrees to be bought.
Why compete for customers? They could form a monopoly to make sure you need to pay their prices, or just threaten you into only buying their products. Unregulated markets eventually stop being markets.
There would be the monopolies with private armies and more money than God to shut down new competition. They can lower prices for years to run at a loss locally to run the newcomer out of money, or just do a hostile takeover.
Yeah, so make it easier for competition. And give antitrust actual teeth. There's massive money flowing into the government and campaigns to turn it into the type of no regulations government you're proposing. So we need to fight really hard to actually enforce those regulations so monopolys don't form.
Yes regulations for smaller companies have been added. And big companies love that. Eli Lilly wants as many tests required as possible even though it costs them money, because they're better able to afford it than their potential competition.