Why did God/Source Creator, produce a physical creation—what was the impetus and goal?

This was viewed as the best arena to launch the idea of complete autonomy and independence from divine control. The advent of free agency and free will for the divine human is a new concept unprecedented within the universe. Beings with this autonomy have much learning and this comes with risk in order to function at a high level and not become corrupted in some way through desire for greater power, or to gain favor and a greater measure of control over others to curate special favor, and so on, at the service of ego. This is the balance and the life lesson it teaches. It is safest to do so in a physical embodiment, in a physical realm, because physical beings are inherently quite limited in their capability. They are relatively immobilized by the constraints of the physical environment. As a physical being in your density, you are subject to constraints from gravity, you are dependent on being in an aerobic environment to breathe and cannot even survive underwater let alone leave the atmosphere of your planet unassisted, so this provides safety by way of containment while the newly created human has been learning its lessons, that is the wisdom in going this route.