The point is to sculpt the life of the practitioner—so that we remember God and His creative presence in our lives in all that we do. Extra work beforehand, moving effort around to clear the Sabbath, then having a weird day on the Sabbath, is a great way of doing that. Acting as a family on the Sabbath doesn’t hurt either!
The orthodox all seem to feel an obligation like that of lay brothers in Christianity. Even there: God is eternal, so prayer cannot change Him. Why pray? It changes us. Why pray unceasingly? For unceasing change.
In most societies, we leave most people at the default shape of life and set apart those who want to sculpt their living of their life. Orthodox Judaism asks that level of commitment of all its members, and so has persisted for a couple hundred years with less change than most.