Q: If reality is an illusion and we only experience perceived reality, then is the illusion of reality merely a product of semantics?

A: Not necessarily; our raw perception, pre-semantical, could be an illusion too. Take color, for example: it seems real as anything to us, but colors don’t exist in objective reality with their exactly three dimensions and distinct qualia, only infinite-dimensional spectral envelopes of wavelengths of light do.

We have means of peering into The State of Things more objectively, but even those observations and the creation of the relevant instruments are ultimately done from vantage point of our bio-sensory perceptions, which evolved to be useful in navigating the environment and procreating—not necessarily to be accurate in any ultimate sense.

You can, of course, scientifically observe our sensory apparatuses to see how accurate or inaccurate they are and in what ways, but ultimately even our observation of our own sensory apparatuses is done via our sensory apparatuses, so there’s the potential for recursive error.

The experiential context we live in could be removed by many layers from whatever form ultimate reality takes. Many physicists think even time itself is an illusion, and that seems way more fundamental to our mode of experience than our semantical assimilation and analysis of it.