How do you define conglomerate? Amazon started selling books. Then it started selling other things. Now it's starting to sell medicine. At what point should the line have been drawn?

Obviously, the goal is to prevent harm to the consumer, but can one demonstrate that the consumer has been harmed? As a consumer, I know it was very hard for me to get such quick delivery of random items before Amazon. I especially remember getting ripped off on HDMI cables and other cables by Best Buy as a kid, and Amazon was amazing for enabling me to purchase them so cheaply, and with such huge selection I never would have found at Best Buy.

(I personally use Amazon.com sparingly now due to their commingling policies and disinterest in providing me with a quality product).

But the point is that demonstrating consumer harm isn't simple. Conglomerates can deliver goods and services at lower prices, which is good for buyers. Conglomerates can also engage in practices which helps buyers in the short term, but harms them in the long term.

Before grocery stores, there were produce stands, butchers, delis, bakers. Then a giant grocery comes into town, and now, as a buyer, I can save time and money going to one place and getting all I need. Should this be illegal?

The purpose of my comment is to illustrate that the situation is not as simple as screaming "monopoly". There are even geo-political risks to consider, where having conglomerates on your side can be helpful, if not help counteract the effects of conglomerates of other countries.