Actually being paid is one of the biggest reasons for a lack in volunteers (the other is people working more than they used to). So many volunteers have been replaced with paid workers. Many charities aren't volunteer run organisations anymore but run more like not-for-profit businesses. As a result it's harder to get funding and donations. And people are less interested in volunteering unless they can be paid for it.
It's a vicious cycle and I'm watching more and more local, community organisations get eaten up by massive, centralised non-profits; and more and more local volunteer organisatns struggling to get off the ground. 😞