We hit on a key point - fiscal policy is about a few different things:
1. Managing inflation - taxing people takes money out of the economy, Government spending puts money into the economy. Tax policy's first job is to prevent the economy from overheating.
2. Wealth redistribution - in the absence of intervention, wealth floats to the top. Progressive fiscal policy takes more from the wealthy and subsidizes the poor, for the good of society (1/2)