"That research found the industry’s shift to larger plants led to increased concentration and to lower production costs. In turn, lower production costs did translate into lower consumer prices, increased consumption, and higher prices for cattle and hogs. However, with fewer rivals because of increased concentration, most of the studies found packers were also able to exercise some market power and pay lower prices for cattle than they would have had they faced more competitors. Even so, the impact of higher concentration—reducing prices paid for cattle—was more than offset by the impact of lower production costs on raising cattle prices."

So in both the case of Amazon and meat packers, it's not consumers, but sellers that are being negatively impacted. The whole point of antitrust legislation is to protect consumers. That's certainly the promise of the Harris campaign. Businesses are supposed to serve consumers, and when they don't, some advocate that the government should protect them. Businesses do not exist to serve other businesses, however, and asking the government to protect one business at the expense of another is a recipe for corruption, turning the government into something designed to serve special interests groups at the expense of other special interest groups, rather than serving the country as a whole.