Earlier quoted context omitted.
The essential feature is subjective experience of sensations, referred to as qualia . I've seen no debate about that. https://en.wikipedia.org/wiki/Qualia
The first sentence on that Wikipedia page: "In philosophy and certain models of psychology, qualia (/ˈkwɑːliə/ or /ˈkweɪliə/; singular form: quale) are defined as individual instances of subjective, conscious experience" Shows that qualia is defined in terms of "conscious experience." If qualia is an essential feature of consciousness then the Wikipedia definition is a recursive definition. The definition of the word…
"The thing that is indicated when you say 'that thing there!'"
appears linguistically empty, because its meaning is not found in the words, but in something extra-verbal that it is intended to point to.
The problem in the debate surrounding consciousness is that there are two basic positions to hold, which are often talking past each other:
1) Oh yes, I see what is being indicated! There is something to discuss.
2) There is nothing here but a meaningless verbal tangle which will disappear when it is untangled.
This problem is similar to, but more intractable than discussing the color blue with someone who has always been blind. The blind person may never actually experience what it is to see blue, the 'qualium,' but there are physical hooks such as the associated frequency of light, and a tangible consensus amongst those who are not blind as to whether an object can be called blue or not.
The latter is missing from the problem of consciousness, which makes it a far more difficult and fascinating problem.