If you don't mind, I want to quickly do a shout-out to the housing volunteering program that Luisa Atkinson spoke about. It seems to me that this is the kind of volunteering program where there is an immediate benefit to those who volunteer, in terms of developing housing that they can live in or benefit from, or that improves the housing condition. Maybe that's a bit of an answer to your question as well, in the sense that even if you work for free, it's not exploitative if you develop something that directly benefits your own community. More of that would be great.
On May 28th, 2018. See this statement in context.