Also, if that inefficiency is in the form of salaries or domestic spending, it's only partly wasted as it adds to movement of money in the economy.
If you pay someone to do nothing you waste both the money you used that could have gone to something useful and the time of the person that would have done something else, hopefully productive, instead.
Unless you want other people to pay for it, of course.
Democracy is not a justification for payment. 51% can vote to rob the other 49%.
But lets say I go down this path with you, one that is not only not how democracies work, but a reprehensible if it were. Lets put it up to a poll then. Lets vote for all these issues and see what happens. The results might surprise you. I have seldom if ever seen a vote for a tax increase to pass popular support.
In my town, in addition to the normal local taxes, there is a special greenery fee/tax that all residents must pay. It is only $25/year. The purpose is to pay the upkeep of all the green spaces which there are many. I happily pay this because I like to walk through these green spaces. Individually there is no way that $25/year would pay for that, but collectively the town can afford to and it improves living here for all the residents.
There are of course many examples where tax money is not used wisely, but there are also many examples where it is. We should get better at spending it wisely which is of course easier said than done. But to say that taxes are like throwing money into the abyss just doesn't stack up to the data.