>reality is all that which is extended in space and time
You are missing the fact that "space" and "time" are also illusions painted on consciousness.
we need to distinguish accounts that are merely self-consistent, and those that are more useful.
the reality-is-illusion meme is self-consistent (panpsychism, simulationism, dream-of-god-ism, whatever). merely being self-consistent isn't good enough.
the alternative (and there is only one) is physicalism and its epistemology, science. the main appeal of this is parsimony, often referred to as Occam's Razor.
Alas, no I am not.
They're properties of the world which consciousness measures.
A mountain is painted in the ink of a photo, the mountain is not an illusion. You're focused only on the measurement, and not what is measured.