Well this question is a bit of a loaded gun, here is my thoughts:
Governments are pretty much from my experience reactive as opposed to proactive. Meaning they wait for a problem, then react to it.
I've worked in 3 different levels of government, and the reality is that for the most part they deal with issues that have the spotlight. They try to be proactive and will put a good spin on things, but in reality they tend to deal with issues instead of preventing them.
Based on my experience, if an issue of the day (River systems, welfare, social housing, infrastructure, fiscal policy, you name it) is for the most part taking care of itself, the government will spend less time, energy and money dealing with it. So from this perspective the volunteer work, while great for our systems, this work will most likely delay government intervention (From my experiences, and in my opinion). The longer it is not a pressing issue, the longer the government does nothing. It's the age old saying, the squeaky wheel gets the grease right?
I'm not proposing people stop volunteering and giving to good causes (Whatever the issue or cause is), however if that volunteering, and or cash donations is done and then not followed up by any noise, it will undoubtedly delay government actions.
What will help bring governments back to the table is NOISE (Petitions, letters, media exposure, etc.....) Remember they REACT to crisis's and issues. If it's not in the spotlight, chances are it won't be brought to the table.
To sum up my thoughts, it looks like this:
Volunteer work/Donations with Noise = Govt Action
Volunteer work/Donations without noise = Govt Delays
Just my thoughts, agree or not there they are. What do you think?