In the US at least, large corporations are also at least theoretically beholden to the small number of (admittedly anemic) labor and safety regulations we have. Small businesses are often just straight up exempt, and so can get away with being dangerous hellholes for employees to work in without really any meaningful recourse. If you work on a large corporate farm, for instance, there are a huge number of safety regulations surrounding how you interact with grain silos. Output chutes are required to have lockouts for when people enter the silo, it's mandatory to have safety equipment on-site, the silos have to be designed with escape mechanisms, and so on. If you're just a kulak smol bean family farmer, though, you can send your 12 year old kid in to "walk down the grain" without even closing the output chute, and it's totally legal. Guess where the vast majority of grain entrapment injuries and deaths happen.