"No longer"? When were they accountable to the public? To public opinion, sure, but we still have opinion polls and politicians in most Western countries spend a lot of money on trying to shape that. But accountability is incompatible with centralization and multiple layers of delegation.

There's also the rather obvious conflict of interest between politicians needing/wanting money and politicians being supposed to represent the will of the people (rather than the will of those who can give them a lot of money). That police officers aren't being bribed doesn't mean we don't have corruption. We just have corruption with Western characteristics.