“Why do we find subjectivity so baffling, compared to the world of objects which seems more mundane and commonplace?”

Do we? Subjectivity is synonymous with experience. As far as we know mundane objects have no experiences. Technically, that can be said about human body too. There are only processes. Subjectivity is that which knows them. So again, do you know of any other point of view in which experiences are perceived than first person subjective perspective?

“mind could somehow be nothing more than a material thing”

Mind is a material thing. That's no secret. It is at all times just a particular state of brain (and perhaps also rest of the body). Exactly as software is always just the state of associated hardware. That people twist themselves into intellectual pretzels due to the fear of death is IMO a completely different matter.