For the record: I personally think that Bitcoin is the only part of crypto which is partially useful. Of course it is mostly used for empty speculation and buying drugs, but there are transfer and legitimate payment sides of it. Too bad its cost for the humanity is disproportional.
Ethereum network is a nice exercise in distributed computing, but its usefulness is questionable, while harm is undeniable.
Everything else crypto are either scam (I estimate this at 90%) or solutions in search of problems.
For the record: I agree except "its cost" part. Bitcoin consumes less energy than cloth dryers. It is not "cheap" for the environment to mine gold, haul it around the globe, have those gold shops, build storage for gold etc. etc. This is not even considering whole banking system.
Drying machines makes life of a lots and lots of people more comfortable. Hundreds of millions is my lower estimation, maybe even billions (if we include industrial dryers used in textile and clothes-making). Useful segment (eg except speculation and illegal activities) of Bitcoin operation is consumed by millions of people tops, two or three orders of magnitude less. And I never heard about using dryers for drug trade.
Ethereum network is a nice exercise in distributed computing, but its usefulness is questionable, while harm is undeniable.
Everything else crypto are either scam (I estimate this at 90%) or solutions in search of problems.