Could a breakup of Kraft Heinz be inevitable?Warren Buffett's Berkshire Hathaway (NYSE: BRK.A)(NYSE: BRK.B) holds many prominent household names in its portfolio. But not all of them have been doing well in recent years. A great example of that is Kraft Heinz (KHC -0.35%). Despite being a big name in the food industry, it has been a brutal investment to hold -- its shares are down 17% over the past five years.The business isn't doing well, growth is stagnant, and investors are worried about the future as co ...