WRT Taxation (after looking at some of the comments posted here):

Governments usually use taxation for two things:

1) To generate revenue; and

2) Socio-economic engineering/economic manipulation.

Reason #2 is why the tax code is so complex and long. It is subject to a lot of abuse and corrupt practices which result in a lot of carve outs, exceptions, and differential rates for "favored" groups and activities. Most of this stuff does not rise to the level of general public awareness (especially the not-so-attractive and more corrupt stuff) or when it does, the awareness is very simple in context and content and subject to (and used for) a LOT of misleading information.

One of the things that could clean a lot of this stuff up is separating #2 from #1. IOW, divorce #2 from the tax code and change it to normal appropriations (open payments/subsidies to the "favored" groups).

Of course, this is unlikely to happen as it would make a lot of this stuff more visible, open, and understandable to the public.

The government (and society) also has a decided interest in limiting and controlling wealth disparity (note I do not say eliminating nor do I intend that). The problem is that the people in government do not have that interest nor do the major donors that fund their election and re-election campaigns.

Wealth disparity = power disparity--and a greater disparity in one area leads almost inevitably to an equivalent disparity in the other area. The Founders understood that there needed to be limits placed upon the power of government and of individuals/individual offices of the government (which we have increasingly ignored over time)--but they did not extend this to the private sector, where it is just as much if not more of a problem. This is particularly true when you combine the power of wealth in the private sector with the power (because of that wealth) to subvert the government.

Reducing the power disparity would be good (I believe) for society at large. It would also be good for our politics and governance. The revenue that resulted would also potentially help with a lot of the socio-economic problems that have given rise to our political problems (because people feel that both the government and the private sector are kind of screwing them over--and they would not be wrong).

It would take a better class of people than we currently have running things--people with better character, less beholden to and more independent from the wealthy. It is another pipe dream that I have.