There’s a lot of truth to that. The less democratic and more authoritarian a state is, the more likely the ruling class will pilfer the people by rigging things in their favor. Just look at Russia: an entire major country that’s been captured by one man and his thugocracy and made to serve their personal and financial interests — with awful consequences both for Russians and their neighbors. You could say similar things about China, which is a kleptocracy despite their propaganda of “communism.”
Economic equality on some level is a goal of every democracy. People should be able to strive and enrich themselves through honest means, but there are limits.