Bitcoin as a currency doesn't solve any problems for people in developed countries. For the 5 billion plus who are underbanked due to lack of access or government red tape, it solves a big problem. Maybe you live in a country where there is hyper inflation like Venezuela or Argentina, or you are a female in Saudi Arabia and you cannot open a bank account, or you need to purchase prescription drugs online because you cannot afford it. Bitcoin is not perfect, but it actually solves problems for some people. We mostly buy Bitcoin in the west as speculation.