Consider what would happen if the tax rate was 100% across all tax types, and you'll probably see then how there's an upper limit to how much tax revenue can be raised by a government. Would you get up and go to work if you got to keep 0% of your earnings? How about if you got to keep 1% of them? 2%?

Surely we can agree that there is a threshold, even if we don't agree where that threshold is. That's all there is to the point I'm trying to make: tax resources are limited and therefore all governments must ultimately allocate those limited resources and cannot simply spend unlimited amounts on any "good" projects that they'd like.