if the average is not sustainable they would need to raise the average or lower costs until a balance was reached

I think you misunderstood what you’re responding to. This would create a situation where being in politics is only not sustainable for people of average means. People who are already independently wealthy would have no trouble at all sustaining themselves on an average salary and have zero (0) incentive to do anything to make life easier for you or I.

The problem isn’t that people in Congress get paid a decent wage. The problem is they have so much money from their families, from their businesses, and/or from lobbyists that they’re more or less totally divorced from what life is like for most people