You are 100% correct. A lot of these governments are corrupt to it's core.
Even if governments are corrupt to its core, I think it is still the citizen's duty to still pay taxes despite their leaders being corrupt. Even if they are corrupt, they are the ones leading their country and it is no easy feat. At the very least, they are the ones enforcing the rules and regulations that protect the citizens from harm caused by criminals and terrorist and IMO, they should be paid for that.
All of us are already paying taxes because what we do involving money is already have. It is base also the income of every one of us because as of now it is rated according to the salary of individuals. In short it's by bracket.