The major issue is that as the years go by, the average salary becomes insufficient because we are spending more and more time working for the government. Let's keep in mind that many first-world countries are being governed by socialist or similar ideas, where politicians need to keep the population ignorant and poor in order to manipulate them. All of these decisions come at a cost, and as time goes on, the state grows larger and the expenditure increases, leading to higher tax burdens, which are ultimately paid by the private sector.
I think the salary given by the government is more than enough to meet our daily needs but it will not be enough to fulfill too many desires, if only we can control our desires then I think the salary we get will be enough to meet our needs.
Their politicians will always hope that their citizens will still feel the need for them, even though what some politicians do will not necessarily result in policies that benefit many people because they will always be tied to those who have brought them to that position so that the policies they issue will be very dependent on only a few of their groups. Of course this will harm many people and the high tax burden will of course be very troublesome for some people who have a small income but not for those who issue policies that will get greater benefits from the tax.