The only thing I can say for a representative system, such as a Republic vs a Democracy is that in a Democracy, everyone turns into factions, majority rules, and stomps on the minority, whereas a Republic will protect the minority's interests - at least better than a Democracy.
Democracies also vote themselves money until the entire society collapses on itself, landing in, usually, some sort of totalitarian system.
^This^ is true if there are no controls on taking money. Sure if everyone is taxed, they want their money back. But when you have to actually contribute to get paid, it doesn't collapse. This is a fundamental uniqueness with the current Dash voting system. Budgets get voted in only if masternodes have confidence it will improve Dash. There is always the threat of no votes, so it is a self correcting system.
Pretty much every economic system is controlled by the top 100 richest people/corporations. Even the best governments have been bribed to get certain laws/benefits passed growing government until it collapses. It isn't anything new. Is there even any democratic system in place anywhere?
Unfortunately, it's the best we got, and it's why I have said before, we may want to make a budget proposal some day for a lobbyist who will protect crypto interest and freedom in Washington and the States, as well as Europe or anywhere where it can be effective. Lobbyists are often awful, but they are a way for a group of people to get themselves heard. More often employed by industries, lobbyists have also helped to pass many laws that were genuinely needed for many minorities. People of other ethnic backgrounds, children's rights and protection, elderly protection, etc... In fact some of those lobbyists are the biggest in the industry and are borderline or indeed too powerful with much farther reaching interests than the people initially supported them for.
Still, at some point, the Cryptographic Currency people will need to fight the Banking lobbyists, and we might as well at least have a big, powerful law firm at our side, at the very least.
Just putting that out there for food for thought, we have a long way to go still ;P