Bitcoin can serve as a sort of value (investment) and medium of exchange (currency) alternative to local investments or currencies that may be unreliable or subject to manipulation or corruption or inflation that is overly erosive to spending power. These things are more common in developing countries but serve as a good "checks and balances" for developed countries.
Blockchain provides greater social impact by allowing greater trust in documents or information related to transactions.
For example, in a country where voter fraud or election corruption is prevalent blockchain technology could be incorporated to track votes and provide incredible security to prevent vote tampering. This doesn't ensure that coup attempt doesn't happen, but at least it keeps the vote pure and this is a start to solving political corruption problems.
Another example, if product supply chains are aligned with blockchain technology companies and consumers can ensure that materials used for products aren't sourced from illegal or unethical (blood diamonds) means.