Blockchain technology hasn't contributed anything of lasting value, and too much money, energy, and good will has been burned by people trying.

Its most popular applications are cryptocurrencies, which are used for gambling, money laundering, and for collecting payments from ransomware victims. Someone once bought a pizza with them, but since that time their transactions have become too slow and their value too volatile to exchange them for anything so concrete.

Various attempts have been made to use blockchain technology for public or shared databases, but it turns out to be worse than all the other faster and much simpler existing solutions in that space.

Others have attempted to bolt it on to various business and social systems, but it hasn't provided any practical benefit there either. It remains a slow and cumbersome alternative to every problem.

Its unique superpower is that it can be used to make contracts between parties that have no trust in one another and no social or legal system of enforcement, so long as your definition of a contract is sufficiently narrow, can be reduced to terms understood by the world's slowest logic engine, and is perfectly encoded the first time around and doesn't require any adjustment thereafter. If one or more of those conditions fail, you'll find yourself turning to the social and legal systems of enforcement you thought you didn't have.