Here is an example:

A new product like steem is launched with a statement that we will NEVER down vote your content due to the topic of the content or your opinions.

Allow people to FLAG (without monetary, or visibility effect) and those flags would accumulate. A central authority would then be able to look for fraud, abuse, plagiarism and the flags would be like a priority queue to help them identify such things.

Now how they deal with that. Should they have the ability to remove such posts? Should there be a reputation system where confirming such activities begins to penalize accounts with a bad reputation some how?

Such a thing could work for awhile. Then the old "who polices the policemen" issue arises.

We haven't even solved that outside of computers.

So "doomed to fail". That is hard to say "doomed to be corrupted" is likely always true. The question how long does it take for that to happen, and do you happen to be able to operate there and enjoy it before it is corrupted?