Not to mention that centralization makes it easier for the electorate to monitor the details. If you look for egregious corruption gone unpunished you find it in the most petty of places for lack of oversite.

I suspect more centralization could help with accountability ironically but there are other issue there including harmonizing different needs and values by region and deciding "who is right".

The three things to optimize and balance are "sensitive to local demands" (treating water by conservation needs in the desert or by great lakes or demands of road salt by road area regardless of climate would be a terrible idea), "ability to scale and administrate effectively" and "respectful of rights" - and all three may clash or agree.