Sacred geometry represents the progression of forms. As a form grows, it expands outward from a center, tending to organize its matter into the simplest shape possible. What starts as a zero-dimensional point, the Absolute of something's beginning, is a sphere, and it is also the form to which all forms return. As it draws sustenance into itself it processes energy from the center outward, pushing in linear directions so the form gains edges, corners, limits. The human being, initially conceived as a spherical form, progresses to the shape of a star. The "points" of the human form - head, two hands, and two legs extending from a center - are also the means by which we organize the world. (This is why the pentagram represents mastery over nature: the five points of contact between the human form represented by the star shape, the world represented by the circle surrounding it. The inverted pentagram thus represents humanity turned upside down, his contact and means of changing the world distorted by his inverted state.) Further, this progression is fractal - observe how limbs become digits, enabling finer control of the world around us.
Civilization is similarly "geometrical" in the way it progresses. The symbolism of the pyramid only tells part of the story. A pyramid presupposes some grounds to support it. But civilization as such, as a form growing and accumulating matter into itself, must grow outward in all directions from a common center. It begins as a sphere, processing matter through itself outward, creating points of contact between itself and the world so as to gain mastery in the same way a human masters the world through his head, hands, and feet. The shape of civilization, imagined as a thing unto itself in space, is a dodecahedron. The points of the dodecahedron are cities, and the valleys are rural areas.
When civilization collapses, it does not necessarily revert to nothingness. Regression tends to a spherical shape. The processes organizing matter into its respective pyramids must remain active for the matter to remain organized as it is. When those processes are inactive, the matter falls subjectively "downwards" like gravity, smoothing out equally to a subjectively "flat" surface. Just like our individual perspective of the earth can make it appear flat, so our perception of civilization can make it seem flat, when in fact our individual perception is limited from seeing all of it at once by a horizon.
Most people are in a metaphorical valley when they try to perceive civilization. They can see the sky above them, the ground beneath their feet, and the mountain sides surrounding them on all sides, but they've never left the valley and have no sense it is only a small part of the world. In fact, most people believe there are evil spirits outside the valley, so they inculcate themselves into a superstitious fear of the outside world and treat anyone who even wants to explore outside the valley like a heretic. Basically, anons are trying to persuade others to explore beyond the valley they've grown up in all their lives. This is why it's so difficult to persuade them to even look, but it also explains why most people are ready to abandon the limited perspective they grew up with when they realize the outside world is, in fact, just as safe as the valley they grew up in.
Anon, thank you for sharing your dreams. I can sense you are being shown these things for a reason. You would not be here otherwise.