Meal prep kits were supposed to make the supermarket obsolete. The opposite has proven true. Now the companies that make the kits may need to partner with a grocery chain to survive. Early leaders like Blue Apron and Plated quickly declined as competitors and grocery stores replicated their service. And Amazon, which dabbles in meal kits, lurks in the background with its ability to disrupt entire markets. Shares in Blue Apron (APRN) have fallen 75% since it went public last year. The company reported another round of disappointing earnings last week.