“The U.S. meatpacking industry is dominated by the "Big Four"—Tyson Foods, Cargill, JBS, and National Beef—which control 80-85% of the beef market and significant portions of poultry and pork”
There are USDA exemptions for tiny producers (up to 20K/yr vs 150K+ for a single modern broiler house) to slaughter and package themselves for in-state sales but anyone operating under one of those exemptions won't be able to grow that business large enough to self-finance constructing their own USDA-monitored facility.