For a country as large as the US? Do you think that you can convince millions of people to willingly and consistently give the TRILLIONS of dollars per year to cover the the cost of the various services that US citizens take for granted. Not to mention actually dividing up such a large budget, so its allocated properly. You do need some sort of centralized body to organize and regulate this.

There are already countries where governments provide little to no services for their citizens and leave them to fend for themselves or organize “people’s led initiatives” as you said. It’s not working out well for them.