Unless I misunderstand your question, isn’t the obvious answer just short-term profit?

No investor has thus far invested something they can’t yet cash out.

If there's no better growth story probably people have already trimmed for short term gains.

In some ways the technology companies, which such large growth, are their own consumers.

Unless they feel pressure from another growth story or a technical monetary effect, and I emphasize story because its about future returns, its unlikely.

Additionally this has grown so quickly that there is amazing talent being applied to these problems, its hard to imagine every good person has been sufficiently compensated that progress will stall.