Politicians are generally driven by the same thing as all of us: they want to keep their job. So elections are still the way to hold people accountable for their promises.

Corruption is a justice system issue. Blowing up the election system will not fix it. I think it will make it way worse because every mayor will know they are going to get kicked out of office in a year or two, or at the minimum have to raise money for constant elections (so we simply get more politicians in corps hands).