The underlying problem that blockchains solve is 'distributed consensus'. This is a solution with a much broader range of applications. For example Maersk has a system for signing handover of shipping containers in ports (https://www.maersk.com/apa-tradelens). This is an international problem with a lot of it happening in countries with a lot of corruption (i.e. you can't rely on legal mechanism). Not being able to forge who is responsible for which container eliminates a lot of problems.
Ethereum does something even more interesting, which is that the network can agree on the result of computations (these are called dapps for "distributed apps"). These can be used to implement simple "smart contracts" for financial purposes but they have a much broader applications. To some extent I'm slightly underwhelmed by the things people are doing with them, but the potential is enormous.