This was addressed by Matt Levine in today's Money Stuff. The problem was not the presence or lack of competition, it was a technical failure of the market structure. Matt:

This is a familiar story and you probably know the ending. There’s a big market (egg producers selling eggs to supermarkets etc.), and there’s a small market (egg producers selling extra eggs to each other on an electronic exchange). The price in the small market determines the price in the big market. Participants in the small market are also participants in the big market. You can spend a little money in the small market to move the price, which can make you a lot of money in the big market.

Not defending the bad actors here, but there's that whole "show me the incentives and I will predict the outcome" thing. If the market structure rewards manipulation, you get manipulation. The market structure doesn't have to be this way.

And notably, we used to have a somewhat progressive corporate income tax which, at least on paper, provided a quantitative disincentive against too much consolidation. Sometimes the merger of A and B would pay a higher rate than A and B separately. And we gave that mechanism up.

I'm not typically a fan of government intervention in markets but Canada's marketing boards do stop this sort of concentration, so while we have higher average prices we do not get massive swings in prices, nor the physical conditions that come directly out of production consolidation that lead to events (or justifications) like avian flu at the same scale.

I think perhaps the USA's modern decline right into the toilet is the result of changes made in the 80's, like gutting anti-trust. What we're seeing now is just the visible manifestation of corruption that has been allowed to grow and metastasize since then.

An assumption required to make capitalism work efficiently is that customers have meaningful choices. Trustbusting is one of the important roles of the government, if it were functional.

We were stuck in the Gilded Age for decades before Roosevelt came along and started big trust-busting efforts. I expect a similar situation to play out here. We're probably in the middle of it in retrospect.

Do decentralized banking is better for business competition and market health.

But we live in a too big to fail, regulatory capture environment.

Most true small businesses can't exist in markets with a lot of competition. Highly competitive markets have a lot of fluctuation and businesses with little capital fold when there's a downturn.

In fact, most markets naturally go from high competition to monopoly or oligopoly. You can see this in chips, cars, airplanes, steel, ecommerce(Amazon) and beyond. Indeed, many oligopoly situations only fail to be monopolies through either antitrust activity or through nation-states supporting their competitors (chips).

Agriculture in particular tends to be geographically dispersed so it's harder to have absolute monopolies. But some "harking back" claim of "if we only had small business, all the predatory stuff wouldn't happen" really fails to understand the dynamics of markets. Scale in agricultural production is what allows the low prices you get in stores - But $10 cage-free organic eggs are available at my local coop for those who love small businesses (though I prefer the $2 cage free eggs at nearby Grocery Outlet).