> Is there reason to believe that outcomes would be better with many small players?
Not only is the blast radius smaller, but small businesses are less incentivized to cut corners since serious violations pose a greater risk to their business than large businesses. Corruption is essentially legalized in America via lobbying, but only big companies can really afford to lobby and make huge campaign contributions to sway the government in their favor.
Government is meant to be a check on businesses, but that completely falls down once business is big enough to buy the government. It wouldn't surprise me if quality control at large companies is worse for the simple fact that they know who to pay off if they get caught, as Taylor Farms has here.