The amount of money politicians allocate to themselves is miniscule compared to the total tax take. The issue is the politicians need the money to feed the ever increasing demand from voters for support, services, infrastructure, etc.
Perhaps if legislation were passed where a citizen received an allocation of votes based on the amount of personal income tax they paid annually we might see a change in the response from politicians. The very rich, who tend to pay almost no tax would get few votes. And those living on social security (eg, the unemployed, etc) wouldn't have a vote. All those small business owners who pay little or no tax wouldn't get much of a vote. The politicians would then focus and listen to the demands of people who pay the most income tax. The tax payers (voters) would want their personal tax rate to go down, but would also know that would reduce the number of votes they had. Those with few or no votes would be encouraged to pay more income tax if they wanted to increase their influence.
Meanwhile, having been on a salary all my working life and paid a high income tax rate, I now find myself retired and living on my personal superannuation saving tax free. So don't ask me to vote for the above and become disenfranchised.
Yes I remember the Howard Govt introducing the GST where all the collected revenue would go back to the State Govts on the proviso they gave up all their various state taxes. The state I was living in at the time gave up its taxes by converting them to levies or duty, which they then claimed weren't taxes.
However the major issue is whether the government revenue system should be "user pays" based or "ability to pay" based. The current system is a mixture of both. With 'user pays' you own a Isuzu and pay for the right to drive it on the provided infrastructure. With 'ability to pay' you make enough money to be able to afford to provide the funds to provide the infrastructure whether you use it or not.