This comparison is moot. Home cooking isn't voluntary work in any sense, nor is it in any public interest. Its ensuring your _family_ has dinner. The alternatives (such as takeaway) are each more expensive.
The problem with your take is that free, public labor devalues paid, public work. This is also why its difficult to compete with 'free' services such as 'free email'.
The problem with your take is that free, public labor devalues paid, public work. This is also why its difficult to compete with 'free' services such as 'free email'.