Voluntarists do not assert they will solve all the worlds problems, only liars, thieves, con artists, and politicians make these nonsense claims, and as a result make the situation worse, give the run around, and request more resources. Voluntarism advocacy does not claim perfection, however no government solutions can make claim to perfection either. Holding Voluntarism to a mythical standard of perfection is unfair given frequent and catastrophic government failures and waste.
Not Central Planning
Voluntarism is not central planning, and does not require that one become a road engineer, security expert, economist, and solver of all of life's deepest questions. Generally Voluntarists prefer to leave that up to specialists and entrepreneurs in each field to come up with creative and unexpected solutions, and in exchange for the value they give, receive value in return.
Alternatives proposed by Voluntarists are just alternatives; many of them are expected to be replaced as better technologies and ideas come along, and replaced again, and again, and again. The primary purpose of a voluntarist addressing or explains alternatives is to demonstrate that fears of voluntarism are irrational. Most proposed alternatives are expected to be replaced by better technology, discovery, business models, and ideas.