It solved the problem of paying for drugs which you ordered online. It solved the problem of ransomware payments, before winlockers used to ask for gift cards

It solved the problem of paying for drugs which you ordered online. It solved the problem of ransomware payments, before winlockers used to ask for gift cards which didn't scale well. It solved the liberty reserve problem where the US government shuts down your sketchy no-KYC money transfer platform. At a very general level cryptocurrency has solved the "anonymous online payments"-problem. These are all very real problems solved by cryptocurrency.