If there are relatively few delegates then what you have is effectively similar to todays payment networks, in which a few big players with pre-established trust relationships come to a consensus on who owns what between themselves. You'd have invented an open source SWIFT.

Bitcoin is somewhat like that as well today due to the (unforeseen) power of the pools. But there are workable proposals for breaking that power and restoring Bitcoin to many thousands of voters again instead of just a few. They haven't been implemented but that's because talk is cheap, whereas working C++ isn't.

By the way, I'm not trying to pour cold water on your idea. Proof of stake doesn't seem like an inherently bad idea to me, and I think everyone agrees proof of work seems wasteful, even if in the end it's less wasteful than the current financial systems. But there's a huge gulf between "how about this?" and a working system that scales.