Blockchain has a pretty long history of how it evolved. People mostly credit Bitcoin’s creator Satoshi Nakamoto, but that’s not actually where blockchain comes from. It’s an old concept that was used by Satoshi Nakamoto for a decentralised setting.
Satoshi Nakamoto did an interesting thing where he combined two or three different areas of research and made bitcoin. Proof of work was not invented by Nakamoto, it was invented in the early 1990s as a way to fight spam in emails. What you would do is that before sending an email you would have to calculate the hash of a value, and this value would be the date and the person you are sending the email to. That would be computationally intensive, so if you have someone who is trying to spam 10,000 email addresses, they wouldn’t be able to do that anymore. So that’s where proof of work comes from.
Nakamoto took that, he took the concept of a blockchain, invented in the early 90’s, and he took some research from the consensus protocols research community, and he combined all of them together very beautifully to produce bitcoin. So his core contribution is not coming up with novel paradigms as such, but rather combining them in a very consistent protocol.