There's really no way to know this, as it's all based on subjective experiences in which two people could easily describe the same sensation differently.
That's a bold claim! Actually, there are plenty of scientific experiments that show actual differences between people who report aphantasia and those who don't, including different stress responses to frightening non-visual descriptions, different susceptibility to something called image priming, lower "cortical excitability in the primary visual cortex", and more: https://en.wikipedia.org/wiki/Aphantasia
So we know that at least the people who claim to see nothing act differently. Could it just be that people who act differently describe the sensation differently, you might ask?
No, because there are actual cases of acquired aphantasia after neurological damage. These people used to belong to the group that claimed to be able to imagine visual images, got sick, then sought medical help when they could no longer visualize. For me, at least, that's pretty cut and dry evidence that it's not just differing descriptions of the same (or similar) sensations.
I really don't think so. I can't visualize with perfect clarity, but I can do pretty well, especially if I try. It tends to shift, so "count the stripes on the tiger" doesn't quite work, but I can do the exercise of visualizing a ball on a table and then saying what color it is.
There is no possible way that anyone could honestly describe this experience as "I don't visualize," any more than someone with working ears could describe their experience as "I don't hear anything."
