I find myself puzzled both by dualism and physcalism.

If you stop all thoughts from entering the mind, and just "be" aware, it's blindingly obvious that all that could ever be experienced or known - whether we call it "matter" or "mind" - occurs within that awareness.

Why do people feel a need to posit something in addition to this matrix or Field of pure awareness or Pure Consciousness?

There's not a single scientific experiment ever conducted - or one that could ever be conducted - that could provide even one scintilla of evidence for the existence of something entirely outside the matrix of non-boundaried non-finite awareness,