The tax-avoidance behaviour of the rich demonstrates very clearly the reason we need government,
So you're saying the PURPOSE of government is to tax people, especially the rich? Obviously you think taxes can be progressive to the point of punishing rich people for being successful. What you and people like yourself have failed to realize is that rich people are simply able to avoid taxes, and will do so whenever and however they can. This is not evil, or bad, or even wrong at any level.
However, the premise that taxes can ever be progressive is simply wrong. My prime example is the "luxury tax" enacted early in the Clinton years, that taxed, quite heavily, things like boats, airplanes and expensive cars and whatnot. The idea was to extract extra revenue from these "rich" people's toys. What ended up happening, in classic case of Tax Avoidance, was that section of the economy practically ceased to exist and large numbers of "average" americans lost their jobs, AND the revenue actually dropped. The rich simply stopped buying their toys.
This ended up hurting ONLY the middle class workers. The rich were still rich. The government didn't get the revenue they wanted, and it was quickly and quietly reversed.
The fact is, you tax the rich enough, they leave, and you don't get the revenue you wanted, and the people working to service the rich lose their jobs. Regressive. Period.
We have that now. And it isn't just the "rich" it is those in power that we serve. And yet, you think bigger more powerful government will lesson our serfdom. I actually think big powerful government IS the problem, because of the very reason you say is the cause of the problem. It isn't the cause, it is a symptom of the problem, and making a bigger, more powerful government isn't the solution.
Money will always buy power, however, the role of governance is not to tax, as you suggested, the rich, it is to fairly govern power so that all are equal before government. This meas we have to stop group politics and go back to protecting the rights of the citizen(s). Abuse of power is always done in the name of the group.