That's an excellent question that goes to the heart of crypto's philosophy. The common answer is Satoshi Nakamoto, but that's more of the "who" for Bitcoin specifically. The "what" and "why" of cryptocurrency have much deeper roots. It was the culmination of decades of work by cryptographers and a movement known as cypherpunks in the 80s and 90s. These were privacy advocates who believed cryptographic tools could create social and political change by giving power back to individuals. Before Bitcoin, there were several crucial attempts. People like David Chaum invented digital cash (eCash) in the 1980s using blind signatures for privacy. Later, proposals like Wei Dai's b-money and Nick Szabo's bit gold in the late 90s outlined decentralized digital currencies but couldn't solve the double-spending problem without a trusted third party. What Satoshi did was ingeniously combine these existing ideas—proof-of-work, cryptographic hashing, a peer-to-peer network—with the breakthrough of the blockchain to solve that double-spending issue, creating a system that requires no trust. A great article that ties all this history together in one place is this one from Paybis. It connects the dots from the early visionaries to the anonymous creator: https://paybis.com/blog/who-created-crypto/
