Speculative bubble getting bigger and bigger by attracting greater and greater fools. No matter what Elon does or says, it's just a zero-sum game. What would the humanity lose if Bitcoin disappeared right now? Absolutely nothing (except people who hold it would lose their "investments").

To the second point, you should look into the definition of monopoly. Amazon is a behemoth, not a monopoly. And they have created immense value.

Yes, that crypto thing was a real damage for humanity.