Why DPoS and not PoS?

A major advantage of Delegated Proof of Stake (DPoS) consensus algorithm over Proof of Stake (PoS) is that in DPoS your vote, which is a deposit to your savings account, works for you the same way as supernode works in PoS, but you don’t need to host and maintain the supernode. There is no need to run an authorizer node, just vote for the authorizer you support and get a share of their income. So the hard work - hosting and servicing the authorizer nodes - is done by skilled people with significant resources which ensures the fast uninterrupted network service. And at the same time even a larger group of people, who still want to be an important part of the project but cannot or don’t want to work on it full time, can become the network stakeholders by simple voting.