Bitcoin was originally created as a decentralized, alternative payment method. Unlike the international bank transfers of the time, it was inexpensive and almost instantaneous.
An added benefit for merchants (less for users) was that it was irreversible, eliminating the threat of costly returns.
However, the improvement in national payment methods and the rapid development of alternative forms (not cryptocurrencies) of international transfers have reduced bitcoin's advantage in this area, especially due to its increasing rates and frequent network bottlenecks.
In some parts of the world, Bitcoin is still a more efficient and cheaper way to transfer money across borders, and multiple remittance starts make use of this feature. However, Bitcoin's cost and speed advantages are eroding as traditional channels improve (and network fees continue to rise), and liquidity remains a problem in many countries.
In addition, a number of large and small retailers accept cryptocurrency as a form of payment, although reports indicate that demand for this feature is not very high.
And many people feel more comfortable holding a portion of their wealth in securely-stored bitcoin, when a central authority cannot block access or cut.