Generally about 30% welfare, 30% education and 30% health.

Sure. But that's my point. It's the output of the tax system that matters almost entirely. The input being high or low is only relevant if the output is good. If the output is shit, yea, then we should lower the taxes.

So we shouldn't really argue for raising or lower taxes, we should argue for spending it better.

How? When social security is like 75-80% of all spending you really cant do much other than cut welfare, that brings its own problems.