When we look at the history of computers in early days having a computer is not a common thing, only the people and companies who had millions of dollars were able to own a computer. And it is true that, it started as a central based computing with time sharing. So if we want to get a computer job done then we had to go to the operator and submit our job and pay the cost. Gradually technology evolved and owning a personal computer became a common thing. Almost everyone has access to a personal computer now.
So Mainframe based computing had evolved to distributed computing, simply we can do almost anything with our personal computers, and they are more than 1000 times better than early days computers. But I think we are going back to the central based model of computing again, the reason behind my argument is cloud computing.
With cloud computing all the resources in a central place (there will be number of centers), and someone will be responsible for managing all the hardware and provide that as a service HaaS. And will manage software for us and provide Software as a service SaaS. So what we do is use those services and pay the cost based on the time we used. It is like taking a taxi, we do not need to worry about anything like, maintains, parking etc.. . So I consider cloud computing as something almost similar to those old days central based computing, in fact in large scale.