What is it specifically about the 1970/80s that causes this dip? Was there an explosion of this academic writing around that era or something else to have this effect?
There are a lot of things religion provides that modern society is really dismal at providing: community, care, socialization across class/career lines, relationships with people who live near you, a support system for sick/hurting people, and other benefits
The thing is, none of those are innately tied to religion. We've abandoned churches for what I feel are largely good reasons, but we haven't found something else to fill that void in community and care. We're more insular, more online, less of us know our neighbours or really have a stake in our community welfare in the same way. I don't think the solution is going back to religion.