> So also things like helping kids with their homework or giving people courses in your hackerspace, repaircafes, reading with others can fall into that.

I'm guessing it doesn't count if you are being helped to help kids or give courses, does it? So not only it depends on what it is, it also depends on how it is done.

Open source in itself is not charitable, and many people get paid to contribute to open source projects.

My point is that I agree that some open source projects can count as volunteering, just like some masonry work. But I wouldn't say that "open source" should count as volunteering, just like for masonry.