We can easily explain how a physical system produces consciousness.

We literally can't do that at all though, not even close.

Because that's literally a basic requirment of science.

How? Science is based on making models from empirical observations about the world and yourself, one of these empirical observations is the observation that your phenomenal consciousness actually exists, seemingly in opposition to the physical world, maybe we should perhaps include that fact in our models?

Also, you call it reductive. I don't think it's reductive.

It's literally how that category of metaphysical thought is called, it's an actual philosophical term.