It's a real phenomena. Mental imagery corresponds to voluntary activation of the visual cortex[1]. The quality of the self-reported imagery corresponds to the degree of activity in the visual cortex[2] while imagining some visual scene. People with aphantasia have little to no visual cortex activity.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595480/

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8186241/

I had thought this was all people misunderstanding each other's descriptions of their inner subjective experiences; but if this is accurate I switch sides.

Electricity in the brain is all we are.

Also its more aligned with the general theory of mind, that destinct variety of peoples would naturally observe destinct variations of sensory qualia and exhibit different internal subjective experiences.

Naturally conscious language fails to articulate these gaps because they are themselves the lack of words.

platos cave, etc

And the claim implied by TFA here is not that the VC is summoning or rendering images, but actually receiving and using a signal to suppress the visual attention from the eyes during imagination. Aphantasics suppress real vision less, so in theory they can’t see their imagination model of the world as cleanly.

I'm familiar with these studies but I don't think you can assume that activity in the visual cortex is phenomenal experience. I'm sure there are differences in self-reported aphantasics and people who don't claim to be aphantasics, but I don't think the existence of differences proves there is a difference in phenomenal experience.