Whether the world "needs" Bitcoin is a matter of opinion, but there are a number of factors contributing to the rise in popularity and perception of value of Bitcoin and other cryptocurrencies:
Since Bitcoin runs on a decentralized network, it cannot be controlled by a single entity like a government or financial institution. More independence, autonomy, and resistance to censorship or manipulation may be possible as a result of this decentralization.
Bitcoin can give unbanked or underbanked people access to financial services, especially in places where traditional banking infrastructure is scarce or nonexistent. Everyone can use Bitcoin for transactions, remittances, and value storage if they have a smartphone and internet connection.
Especially for international transactions, Bitcoin transactions may have lower fees than transactions using traditional financial services. As a result, there will be less expense for businesses and consumers when making overseas transfers.
Bitcoin transactions are documented on the blockchain, a public ledger that cannot be altered. When transactions can be easily verified and tracked, this increases security and transparency by lowering the likelihood of fraud and corruption.
With a 21 million coin maximum supply, bitcoin is a deflationary currency. This cap lessens the chance of inflation, which over time can destroy the value of conventional currencies.