Medium sized business , becomes big, by competeing well ,a company that attracts more customers has an advantage over one that repells some of them.
You're correct-if you are under the assumption that all Chanel boutiques desire to be Wal-Marts.
Mark Cuban once pointed out that he doesn't want his businesses to become too big-comparing business to supernovas, if I recall correctly. Operating under the assumption that all business wants to be giant is incorrect. Many businesses are quite happy(some overloaded)with "medium" pipelines.