Volunteering is a good way to correct the “social systems”, because it comes from the real people, from concrete grounds, not theories.
When a social system is managed only from the top (governement, administration), there is a high risk of non-realistic decisions.
In such cases, the civil society has to intervene.
Volunteering can also be good when the states cannot provide all the necessary services and solutions.
Then, the ideas and actions of the volunteers will be more pragmatic and adapted to the natural reality.