An illusion is a false image of reality. Thus, there can be no illusions without first that which is real. Therefore human consciousness cannot be simply the vehicle for illusions of reality, but must be the vehicle by which man can ACTUALLY know what is real (true) from what is ACTUALLY an illusion of reality (false). Otherwise, there could be no consciousness at all. For you cannot be aware of an illusion of an illusion; where consciousness is an illusion and thus so is reality, by extension.
I disagree with your apparent conclusion. You leave as an assumption what reality is, as if it is obvious and common. If this is indeed the case, then your proof can be Real. But in order to make this propsal as it may argue some true-real aspect, it is not illusion that substantiates what is really true bur only what is really real.
You might ask what is allowing you to discern this consequential polemic. If you say consciousness, then you have merely enacted a circular proof snd begged the question of illusion.
So, there is some aspect that is not illusory nor real-true, something that is informing this situation.
If we assume that there is such a thing as reality, then we by extension admit the reality of consciousness–or, our ability to apprehend it.
If we don’t admit this then we admit that reality is unprovable, because the frame of reference–our awareness of Self–is undefined. In which case we cannot answer the question “what is man?”. In which case, you can’t really disagree with me because you aren’t actually anything at all.