The problem is no one wants to pay for the boring necessary work like funding inspections for the water treatment facility, but instead would focus on sexy cool things like space launches or new trails in Yosemite
Mathematically it wouldn’t do much but it would make people feel more invested I suspect.
Fun fact: the US Treasury accepts donations to pay down the debt: https://www.treasurydirect.gov/govt/reports/pd/gift/gift.htm
You can also donate to the general fund: https://www.fiscal.treasury.gov/public/gifts-to-government.h...