Although bitcoin and the Internet are really decentralized, they pursue different goals.
The Internet has evolved mainly into an infrastructure for an unlimited number of applications and traffic, such as e-mail. On the other hand, bitcoin has a very specific and narrow main task - it is a "digital currency based on the peer-to-peer network", as Satoshi Nakamoto wrote.
Ultimately, most of the services using bitcoin are designed to provide a more effective achievement of its main goal as a means of exchange.
The functional of blockchain network is rapidly growing - such achievements are on a scale beyond modern financial infrastructure.