While whinging about taxes is a national pastime here in the US, we have one of the highest tax compliance rates in the world. These might be related. And it's not true that you can make taxes go away with accounting magic, although there seems to be a growing sentiment that "the other guy is doing it". Example: Bourdain's comment about avoiding taxes by living abroad is nonsense.
Those "transparency indexes" tend to reflect the biases (cultural and political) and the interests of the major contributors to the organizations that produce them (including organizations like OECD).
And unlike measurable data, where you can double check, here you have to agree not just on the methodology, but on the validity of various sources, self-reporting (which is often used as a proxy), etc.
The GINI coefficient may be a better proxy than those targeted measurements.
I guess it's fine to hate your government, but a better solution is to change it than avoid paying tax. Because if people pay less tax then then the poor and vulnerable will be affected first, not the corrupted interest group.