It is human nature to care more about what is mine than about what belongs to another. It is partly pride of ownership, partly self-interest in the value of what is owned. If we have paid good money for something, we tend to take care of it so that it lasts, to use it for all it’s worth.
What is taken from us in taxes is ours, but once taken, it is not; it becomes the property of some government. The government representatives have a fiduciary responsibility to use it for our best interests, of course, but really it is “other people’s money” as far as they are concerned. No one representative in the government controls how my taxes are spent. No one representative becomes its new “owner”. Rather, that responsibility is divided up by all the representatives who vote on budgets and allocations of funds. Once taken as taxes, the ownership of those dollars becomes shared, a common resource, as it were. The Tragedy of the Commons  then becomes relevant. In this circumstance, each representative seeks to benefit as much as possible from the common resource, using it up as quickly as possible for their own benefit, not necessarily for the benefit of those from whom the resource derived.
This describes the current situation of representative democracy. Legislators, and the special interests they cultivate, get “theirs”, without concern for the preferences of those who originally provide the resources (taxpayers). The end result is runaway spending, often accompanied by inflation and debt. Sound familiar?
In the last analysis, therefore, the failure of representative democracy lies in its failure to provide “ownership” of taxes. (I am avoiding for the moment any argument that a government has any right to tax in the first place.)
Can this problem of “ownership” be resolved? Sure, there are lots of ways. A dictatorship comes to mind, where the dictator has sole ownership of everything. That’s one solution, but not a good one.
Another, and I would argue, better, solution is the one that is embodied in the idea of cantons as expressed here. Each canton becomes a new “owner” of the taxes taken by the government from its citizens. Unlike representatives in a legislature or town council, the management of the canton knows to a very great extent how the people who have chosen it to be the new “owner” of their money would like that money to be used on their behalf. In addition, the management of the canton has a very great incentive to spend that money according to the wishes of the canton’s members.
Representative democracy, where revenues are a common resource of an elite, is a fatally-flawed concept. Cantons, where revenues are owned and managed by people operating on the same principles as the original owners of those revenues, provide the fix.
Government at all levels will never be “right-sized” until taxes are owned, and not treated as a common resource of an elite. Owners understand risk, and work to minimize it. Owners seek value. Owners act responsibly, or they very quickly become “former” owners.