Discussion: Is This What We Should Spend Our Money On?

The Federal budget is made up of three parts for planning purposes: Mandatory spending, which is enabled by ongoing appropriations, and so does not require new spending authorization; Discretionary spending, which has to be re-authorized each year; and the Interest on the Federal debt. For our purposes, because we are not looking at the legislative process, it is one single large spending pool. Below is overall Federal spending in the USA in 2018
2018 Federal Spending.
(Links to an external site.)

https://www.cbo.gov/publication/55342

View the document or the Interactive Graphic.
So you can see that in 2018 Federal spending added up to $4.1 trillion, or 20% of then US GDP of $20.5 trillion. Obviously this was more than  revenues, which at $3.3 trillion left a deficit of (a bit less than) 800 billion dollars, or 3.9% of GDP.  We spent 24% of Federal money on Social Security + 14% on Medicare, which = 38% and growing of all US Federal expenditure on retired people. Another 15% of the entire budget in 2018 was spent on the US military. In addition we spent 9.5% on Medicaid, which is medical assistance for poor people. And we spent 15.6% on natural resources and the environment, general science, space & technology, general government, community & regional development, agriculture, administrative costs of Medicare & Social Security, energy & commerce, and housing credit programs. Another 7.9% and growing was spent on servicing the national debt. About four-fifths is spent on retired people, the poor, the military and the Federal debt.
On the Federal level, education spending is allocated to Pell grants, work-study, guarantees of student debt, and Head Start, a program for poor pre-school children. The great majority of spending on education in the US is on the state and local levels, although the Federal government plays a regulatory role.
Similarly, with respect to the environment, the Federal government plays primarily a regulatory role — in this case, most spending in terms of mitigation is by private industry. The largest exception is the national park system; there are also state and local parks and reserves.
Do you think these are the best priorities for US Federal government spending? Do you propose some other set of priorities? If so, what? Write about three paragraphs. Please use outside academic-level sources to support your position.