> You only want people as politicians because they feel it's their civic duty to serve their countrymen, not because it's a lucrative career.

And that's where sortition (vote by lottery) is probably the best system, combined with a way to vote to remove and "Redo lottery".

Whomever is elected by lottery would be provided a "unswayable" amount of money, basically buying corruption away. They would be set for their life.

A lottery of all eligible citizens would also have secondary effects of encouraging high education across the whole populace, so that when Joe or Jane Doe is selected, they do a good job for the citizens.