Yeah, this is a valid critique of the whole internal monologue idea, but interestingly aphantasia has been quite empirically confirmed and the simple apple test has been validated!
I'm saying there are a number of physical tests like the ones you describe, and those line up with the much simpler apple imagery self-report test.
The aphantasia theory is clear and parsimoniously makes sense of all this, but your "it's all just semantics" does not, and additionally requires rather other extreme acrobatics with regards to much of the entirety of human experience and discourse. Scholarly research also basically says this.
Your mind is clearly closed and you do not have any serious interest in understanding anything here.
There are correlations to non self-reported phenomena. This comment names a few (despite being dead for some reason?): https://news.ycombinator.com/item?id=49475441