Cryptocurrencies can be useful as currencies. Not very useful as investment though.

Like with any new technology. Remember the blockchain hype a few years back? Give it a few years and we will have a handful of areas where it makes sense and the rest of the hype will die off.

Everyone sane probably realizes this. No one knows for sure exactly where it will succeed so a lot of money and time is being spent on a 10% chance for a huge payout in case they guessed right.