I find IPA terribly confusing myself, but I think the starting sounds give a decent indication to people how the starting sound of Volk differs more from that of Wolke than that of "valley" from "wool", and it's that latter distinction that is hard for those of us used to languages where that distinction is near non-existent or one of the sounds is rare/not in use.

For an English speaker, to put it differently, while the words as a whole are not pronounced exactly the same, the starting sound of German "Volk" is the same as for English "folk", while the starting sound of "Wolke" is the same as for "valley".