The primary problem with big government is misappropriation of resources.
The government links with large industries, all the biggest contracts are government ones. The government hands out these contracts and carpet baggers enrich themselves, while the JOB either doesn't get done or is done poorly.
So where's the problem, it's not the government structure, it's something far more fundamental.
HUMANS, big (leaders) and small (flock), without oversight will invariably BUILD MONUMENTS to themselves. This takes many forms, big houses, multiple houses, expensive vanity goods, actual self monuments/sculptures, etc.
We as a species have conquered every human need. All we have left are excessive wants that are near universally a waste of resources.
Conquer Excessive-wants at the Personal level, and the system will auto-correct.
HOW do we do that. Communism. It's never worked before, because we've never truly had it.
Codify, if anyone builds a monument to themselves, OFF WITH THEIR HEADS.
Sports cars, luxury watches, no problem, Everyone gets to drive it, it'll blow up in about a week, but we'll build more. But you build a million sports cars just to sit in rich guy's garages, as is the current system, That's WASTE.
If we do no fix the ideological flaws in human society, no form of government will work, it always defaults to the SAME-thing. Oligarchy.