It almost seems like the union of the nodes is what all of the spirituality points to. Ketu is the past, Rahu the future, but their union is freedom from that, leaving only the eternal present moment, which is absolute and total liberation. And this brings up the main question, cuz Ketu's ultimate desire is liberation, right? So the entire point of Rahu is really just for Ketu to evolve it's own perspectives.
That is my conclusion as well. It follows the saying that goes something like “The past is gone, the future is not here, there is only the present moment.” In one of his recent videos on YouTube, Ernst mentioned it in terms of Rahu-Ketu, where he said Ketu is misconstrued memories and Rahu is unclear because we haven’t experienced it yet.
What’s left then is the present moment, each fraction of time taken one step at a time, the best we can do with what we know at that time - millions of still frames that when run continuously making up the story of our life.
Ketu pushes us out and Rahu thrashes us. It is because of Ketu that we venture into Rahu. Ketu castle starts crumbling and we fight our way through the Rahu jungle to ensure Ketu’s survival.
In the process of being comfortable, we forget that by venturing out into Rahu, we get to expand our Ketu, because whatever we acquire in Rahu also becomes Ketu. It is what we have already fought for and made our own, that gives us that sense of belonging and comfort. Eventually, there is nothing but Ketu.