Not even that there is absence of evidence -- but absence of evidence is not evidence of absence. Moreover, your cherrypicking of "Internet-type" inventions that develop very quickly are definitely outliers. By contrast, the answering machine was invented in the 1930's, and didn't take off until 50ish years later.
It's absurdly and ignorantly early to declare "crypto has no utility."
It's absurdly and ignorantly early to declare "crypto has no utility."