I hesitate to come to this conclusion.

When I was a kid, I could visualize things so vividly, I could almost overlay the visual signal onto my real visual field.

The visual cortex signal was "loud" enough that I could trick the propioceptive parts of my brain.

E.g. I could visualize falling so vividly that I would actually feel the stomach drop sensation.

As I get older, I still have a very visual mind, but not nearly what I used to have as a kid. It also feels more "far away" from my actual visual field.

Though some days if I'm stressed, I don't seem to have as much control/access to the visual side of things.

So I kinda get where aphantashisa people come from.