That is of course valuable to other people or the society and it may also be valuable to you because you enjoy doing it. But that is not what I meant. When you do some work to make a living, then you have to earn enough to live on the income. What is the point of working full time and then starving anyway? What you can do voluntarily is not affected in any way, you can make paintings and write open source software for no money as long as you want.