In the below linked presentation, Bitcoin is exposed as a fake investment product, which as such, is a total waste of energy. This also applies to all cryptocurrencies.
Why is bitcoin a fake investment product? Or, to put it another way, how do we even differentiate between real and fake ones. Well, it's easy. In a real investment product, your investment of property or work is invested into something actual, which in the future, can provide you similar benefit. In a fake investment product, your investment is not actually invested into something, but is rather, just transferred from you as a new investor to old investor. Historically, there is no exception to the rule that all such products end up collapsing.
The rest here:
https://youtu.be/N5RKm7_scL4First and foremost, Bitcoin is money, not an investment product. Some people make their savings in USD, also hoping a bit that the relation between the USD and local fiat might change, and thus this would become profitable. This is how I view Bitcoin. Not as something into which I invest and expect it to grow, but something in which my savings are, and something I'd hopefully be able to use more in the future. On the other hand, the line between 'something actual' and 'fake' is very blurred. There are some things people truly need, so investing in it could be called investing in something real. An example is buying a flat which you can rent to others or live in. However, many investments aren't that easy. For instance, when personal computers weren't really a thing, many people did not believe it would make sense to invest in Apple, 'cause who'd need a machine like that at home? Or, even more surreal, let's take something like the first social networks where people could just talk and not 'really talk'. So Bitcoin might get really useful and something people can't imagine their life without in the future, and in this sense, it's not a fake investment if you look at it from this perspective.