They are not the cause, the cause is human nature. Replace them with other people, and after a couple decades we'll end up the same.
Bitcoin: Same thing, we have inequality because people want to amass and not share. At least tho we know the system can't be perverted in the sense of creating random money pressing a button.
Indeed, it is human nature to abuse of force. This is why the idea to give force to someone (almost no matter whom, as you point out) in order to enforce "the common good" will always end up corrupted in using that force for "the oligarches' good".
On the other hand (as username quoted Kant), in order to have freedom, one needs to be free of the arbitrary violence of others, and one needs one's fundamental freedoms to be protected (by force - there's no other way: nothing that is not force, can impose something to something that uses force).
So here's the fundamental dilemma of statesmanship:
- in order to protect the freedoms of the citizens, a violence monopolist who is stronger than any contender (in a certain territory) needs to exist (the State),
- but any one having the authority to handle the State's violence will always end up using the State's means for his own purpose and not for the general good (in as much as that can even be defined).
So a (violent) state is a necessity, and an unavoidable evil. It is even an unavoidable thing, even if it weren't a necessity: *somebody* will end up being the strongest, and hence the de facto violence monopolist. So a state is not only an evil necessity, it is an unavoidable evil.
This is why I'm for a minimalistic state, with as few competences as possible. However, this hope bites in its own tail, because who's going to limit the prerogatives of the violence monopolist ?
My only hope is that people understand the mechanism of power, and generally start understanding the fundamental but unavoidable and even necessary evil of the state.
As long as there are idiots cheering for "more state" my hope is vain. It is like turkeys cheering for Christmas.