1. Time and cost of building and growing a new e-commerce platform, especially for a giant like Walmart is non-trivial. I bet the requirement design alone would

1. Time and cost of building and growing a new e-commerce platform, especially for a giant like Walmart is non-trivial. I bet the requirement design alone would take a year to be approved. 2. Big companies often fail in new and unfamiliar markets. 3. Consider acquisition price inflation. If YouTube was created in this period, its selling price would be near $20B just like WhatsApp.