It is with some restraint that I note that "democracy" per se does a piss-poor job of preventing this, when Tim Cook's net worth exceeds the yearly GDP of the Seychelles. This is particularly true in a world where capital controls information channels, and therefore public opinion. To really prevent capitalists from capitalizing on their capital to amass ever more capital, you also need a social infrastructure that redistributes wealth away from powerful individuals back to society, so that social issues can be addressed.
Yeah, I sure hope that would be true otherwise Apple has some explaining to do.
I'm not sure if wealth is any better distributed in autocratic countries, think Putin's Russia and its oligarchs.
Democracy is a continuum, any country can evolve into either direction. It's not like this country is democratic and that is not. Countries have more or less of it.