You can watch it in real time. You doubt it because most people are taught that markets naturally centralize and monopolize. They don't.

The larger and more centralized a business becomes, the less responsive it is to both consumers and price shocks. The reason scalability works is off of efficiency. The reason McDonalds can make a $1 burger is because they manufacture well over a billion identical burgers every year. It is as simple as a burger can be physically made, it is identical to all other burgers of it's kind, it is made as cheap as possible, with the cheapest ingredients, and is effectively the lowest quality product available.

However, the is a point of diminishing returns. It is not possible to sell every human on Earth the same lowest possible quality product, at a single ultra cheap price, forever. Some price will change, some wants will change. No market can be stable. At that point adjusting this highly efficient and centralized system is impossible. To make a burger with sesame seeds would suddenly cost billions of dollars in developing new logistical systems, new purchasing orders for seed farms, new manufacturing orders for bread, new transportation routes, new regulations internally on how to manage it all, etc.

A small mom & pop store can simply add some seeds onto their bun and adapt to the fad. If people really like sesame seeds, the small business can directly talk to their customers, and can buy some new buns much faster.

For the ultra-large company, the solution is apparent. A billion dollars in production change is unaffordable (assuming they even notice that the customers wanted anything different in the first place). If they actually responded to their customers will, they would need to constantly try and completely change their logistical system on a monthly basis. They can't go from regular buns to sesame seed buns to regular buns in a month or two. They can't switch from red lettuce to green lettuce to romaine lettuce. They can't go from american cheese to provolone, to swiss. They literally couldn't afford to exist. Instead, they can either try to force the market to not want sesame seeds, or they can force the market not to buy seeds from small businesses.

Both require the government, which they happen to be donating huge amounts of money for. First, they put out a marketing campaign from a "concerned citizen group" about the dangers of sesame seeds. Their paid-for politicians can now create investigative panels, speak with "leading industry experts", and appoint bureaucrats to the Health & Safety agencies that regulate food. The media (obviously) will follow along. Once the politicians have generated enough political capital, they will then pass regulations to prevent businesses smaller than the ultra-business from selling sesame seed buns. This will come in the form of crippling regulations, safety checks, added legal liability, and license fees. Suddenly, making burgers with sesame seed buns isn't practical unless your company has over 100 million dollars in income; which only the ultra-corp has. Then, the ultra-corp asks for tax breaks and subsidies to help it and only it from the burden of the regulatory framework that it created.

This is also why you can find some of the largest corporations in the world asking for regulation in the industry. BP Oil wants the oil industry more regulated. JP Morgan Chase wants more banking regulations. Notice how Google has never once censored Elizabeth Warren for demanding anti-Trust regulation? It's because the anti-Trust regulation is good for them. It's a fucking scam.

Without these regulatory frameworks, the market would shift too rapidly for the largest companies to adapt. They would have no choice but to either collapse or decentralized. The reason they don't is because the government keeps them afloat. The government needs them to help control society and socially engineer it; and the business needs the government to keep them ultra-massive.