Comment by jmye

Because we use taxes as a process to crowdsource funding more effectively. That's literally the entire basis for it. Might as well ask why "only the taxpayers who care about a new highway can raise funds to buy it" and then we're back in some weird, system of no central government because someone can always claim "why not just like, let people donate money" because it's a simplistic cliche that appeals deeply to people who aren't quite clever enough to work out just how much they've benefitted from the system as it's been constructed.