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Since the primary function of government is the protection of non-subsistence property rights, it is sensible to charge a use fee for those rights. Note, I said "non-subsistence" property rights. The point here is that house and tools of the trade are protected from confiscation under bankruptcy law precisely because they are subsistence assets. Where government does not exist, subsistence properties are typically defended by the occupant, whose life is sustained by those assets. Government brings precisely the property rights we associate with civilization -- assets beyond home and tools of the trade.
Given the relatively liquid nature of civilization, it makes sense to define "subsistence" in some dollar value of assets. Various ways of defining the dollar value are all approximately equal:
Assessments should be of the liquidation value of the assets. The owner can force the government to purchase his asset at the assessed value. The liquidation value can be set by the simple expedient of letting anyone place a bid on an asset by putting the amount bid in an escrow account with the Treasury, at the risk free interest rate (approximately the interest rate on the national debt), this being the basis for Modern Portfolio theory. Other forms of taxation could be eliminated in a revenue neutral way if net assets, in excess of subsistence levels, were taxed at the same rate.
Indeed, given the centralization of asset ownership that has resulted from the subsidy of non-subsistence property, a subsidy inherent in civilization, it may be the failure to use this tax base is the ultimate cause of the repeated decay of civilizations from ancient times.