The tax system is used by most governments to redistribute wealth/economic activity in various forms.
Income tax is the simplest example of this; tax those with greater means to pay more so than those with less means to pay. By doing so, and providing services and infrastructure such as healthcare, income support, roads, ports etc, society as a whole benefits.
Or, tobacco excise with the aim of raising the physical cost of purchasing of cigarettes to discourage people from buying them. Sure, they are inelastic goods and so they raise a disproportionate amount of revenue relative to the activity they discourage, but thats just the way the system has evolved.
I can't believe the number of times since I've been posting on this forum that people have called for "tax to be lowered" or said "tax is EEEEEVILLLL" or "Government's are trying to screw society over" or "governments are just central planning with democratic lip service". At the end of the day, you pay tax, you get something back. The whole mentality of "I've worked for it, so its mine; and the government cant take it away and provide basic services with it zomg!" is a large contributing factor to why the developed world is so fucked at the moment in an economic sense.
You can't expect to have a decent, functioning society without a government, and a government can run without revenue. Revenue comes in many forms, with taxation the main one ofcourse. Yes, governments have a tendency to get a bit bloated, but they are the biggest organisations in the world. Do you think if Proctor & Gamble or McDonalds served as many customers with as many services as a government does they would be as trim and efficient as they are now? I don't think they could be, happy to be challenged on that.
Sorry, rant over. Please feel free to flame me, troll me, bait me etc.