The silver lining on the topic of the decline of intelligence is that we don't ultimately need transhumanism and CRISPR gene editing to reverse it. It can be reversed by some cultural changes that we can make. And it will not be very many generations before geniuses solve some of the most intractable problems our species currently faces and we began to turn our collective gaze toward impregnating the other planets in our solar system with human brilliance.
The most impactful contribution that you can individually make to a better future is forming a family with a virtuous partner at the earliest possible opportunity.
If you're a single guy saying, "Where the hell do I find a virtuous partner? And what qualifies as a "virtuous" partner...?
I wrote about a book about exactly that, Don't Stick Your Dick in a Blender: How to meet a nice girl instead - from a tantric husband with a better sex life than you!