If you examine the term consciousness you'll find a man made construct used to explain why we are aware of what we are aware even though that doesn't square with what's happening. There is no biological mechanism identified as the conscious or the unconscious. Check. Not even everything to which we attend is preserved in awareness and we only attend to a little.
The term "consciousness" is... just a term.
So, it's just not an explanation and doesn't explain consciousness itself. It is certainly used to refer to different things. For example, maybe the condition of a person in which this person perceives at least part of its environment, for example in such a way that a doctor can ascertain that the person is responsive to some stimulus. It may also refer to the whole of whatever a person is experiencing subjectively (or privately etc.) and only in the particular way that it is experiencing it, whatever that may be precisely. Another way to put it is perhaps to say that this kind of consciousness is the part of a subject's mind that he is paying attention to, focusing on, etc.
I suspect there are other notions of consciousness, perhaps one where it is a synonym of "mind". Whatever the case, the term is not an explanation, it's just a term, and it's what one mean by it that matters. Some kind of explanation may be regarded as necessary, like the physical processes which could explain consciousness (depending on which kind of consciousness you are referring to) but the term doesn't provide any explanation by itself.
Another question is of the reality of what the term refers to. This is where I don't get your take on this. According to the second understanding of the term I offer above, it does not refer to anything explicitly material or physical. It's agnostic on that. Rather, it refers to one's subjective experience of one's own consciousness. I can form an idea of something and call it the idea of a tree. The tree may not exist but the idea of the tree does since I know it does. And I'm quite sure most people, and most scientists, if maybe not all of us, would agree with that but even if they disagreed that wouldn't change that fact of its existence.
In this respect, whether there is or not some physical or material explanation of what I or other people call consciousness is irrelevant to whether consciousness exists. For all I know you may well completely misunderstand the term as I use it or how it is generally used. All that this does is that we don't understand each other. It doesn't make consciousness somehow not exist when I know it does.
You seem to equate the absence of a materialistic explanation as proof of the non-existence of consciousness. This is obviously just wishful thinking. Consciousness exists and we may want to find a materialistic explanation but just because you have none available now doesn't entail anything about the existence of consciousness itself.
Whether we all experience consciousness is perhaps an interesting question and maybe you don't experience what I call consciousness. If you don't you may not believe that I do but that won't stop me from knowing that I'm conscious whenever I am and therefore it won't stop consciousness from existing.
EB