No, qualia are not fundamental to existence, this is an example of Wilfrid Sellars' "myth of the given" - to have a quale of a colour or a shape appearing in your vision you must have a concept of that colour/shape. Qualia in that sense are not prior to cognition. Maybe we can say they are necessary as an element of concept formation and language, ie for sapience.

Ok pain might be a bad example because a robot may not have a sense of it borne of evolution. But what about “red”? If I make a robot that 99.9% correctly identifies red objects, then I think it is fair to me to say it has a concept of “redness”.

Some philosophers believe that our human emotional connection to redness is special. These are the people talking about qualia. My belief after much reading is that it is not special. I /do/ believe that the human ability to tie our senses so deeply together synthetically and into our emotional and memory is special. My robot cannot write a poem about how the redness of a flower reminds them of their mother’s funeral. But now we are talking a matter of degrees, not qualia.