let's say magically the number of tax dollars taken in by the government doubles. How would your life change for the better?

I imagine there could be more spent on improving the condition of the roads, public housing and health provisions, school budgets could be larger, any number of things.

I don't imagine tax take would double, however many billionaires got fleeced, but the premise that the government would necessarily be worse at disbursing the funds than private individuals is laughable.