You don't seem to be getting what motivates people to go into politics. They are not looking for ways to avoid involvement in corruption. The opportunity to be involved in the favors economy is most of the job's appeal. Paying them more would just cost more.

I can see how you can think that's the case if you set up the incentives to only attract those people.

It is the nature of the job to set up its own incentives. How it is is exactly how the people who do it want it to be.