USA is a lot inefficient with spending money as a lot of it get syphoned in one way or another from various interest groups, from big pharma/healthcare/insurance, hedge funds that run universities to local government that run homeless shelter in opaque way (ask Cuomo sister). As OECD data, US social spending as % of GDP is above OECD average at 22.7%[0]

[0]https://data.oecd.org/socialexp/social-spending.htm