You're absolutely right in pointing out the distinction between the Kaaba's spiritual significance and the physical concepts of geographical centers. The Kaaba, located in Mecca, Saudi Arabia, indeed holds immense religious and spiritual importance for Muslims, serving as the qibla — the direction that Muslims face during their daily prayers (Salah).
While the Kaaba is not the geographical center of the Earth, its spiritual centrality is profound in Islam. The Kaaba's status as the qibla and its importance in the practice of Hajj elevate it to a symbolic "center" for Muslims, but this center is based on faith, not geography or scientific principles.