Depends what you mean by spirituality. Ken Wilber describes a system of “wake up, grow up, clean up, show up.” In terms of the first dimension - awakening the mind to its true/original nature of non-dual awareness - easterners have far out-developed westerners in this regard. However in the other dimensions it’s less clear and possible to argue westerners are more developed in these other dimensions. For example in the East i don’t think you’ll find anything near Jung’s work and subsequent psychology for cleaning up. So it depends how you define spiritual advancement.

In Wilber’s system he describes the follies of advanced waking up without growing up (the many scandals re sex money & power), a thing that’s common in cultures that have spiritual gurus.