I'm not sure why one would put this pursuit into the category as "would have no effect" when the pursuit of understanding of what was once called (and often still is) spiritual phenomena has changed the world so much in the past.
If the afterlife is found to be simply another kind of existence, and consciousness and identity to be, say, quantum lattices cohered by "material" much finer than our instrumentation can currently examine; and this afterlife was found, say, to not conform to the rules of most traditional religions, but rather operated from a different set of governing principles ... you believe that if this sort of information became publically accepted as factually evidenced by science, it wouldn't dramatically affect the course of the world over several generations?
To me, that is the same as saying that no science, nor any religion, has ever meaningfully affected the course of human history, because this would be the most dramatic scientific and religious discovery in the history of humanity, IMO.
A scientific means of examining the spiritual and interacting with those in the afterlife and gathering verifiable, information about it? No effect on human history? Wow.