I think the implication of the question may have been "why not just hold the stock after the IPO if you expect.

Further down, continuing the Sister quote:

three examples Suster uses – Salesforce, Google and Amazon – show how much more valuable the companies were after their IPOs. Before these three went public, they weren’t unicorns – that is their market cap was less than a billion dollars. Twelve years later, Salesforce’s market cap was $18 billion, Google’s was $162 billion, and Amazon’s was $17 billion.