Without this theory, science assumes no such thing, and ultimately ends up with a very difficult problem of defining where consciousness begins and where it ends.
Existence of consciousness is obvious and intuitive to most people, it is rarely disputed (and such disputes yield no useful conclusions or thoughts when they take place), but if the starting point is that "some humans have consciousness, or a potential of a consciousness, and the rest of the world does not", then the problem of defining it seems very hard. Drawing a hard border between consciousness and dead matter seems hard to do while still being completely intellectually honest.
If however, we just assume (as the perennial philosophy does) that consciousness (or at least potential of) is a self-evident property of reality and everything in it, we can view the problem of defining it as more of a question of where in the world is there "more" of this consciousness, where is it more concentrated, where did the potential of it most prominently manifest itself (places like human brains that host it or possibly similarly built computers in the future), and where is it "less" of it (like in a rock formation), then we can use this framework to more easily navigate this landscape.
For me the promise of philosophy is in examining the deepest assumptions that we use to interpret our experiences and guide our thinking. This is a hard task because just like sea creatures that are surrounded by water their whole lives and thus don't notice it, we don't notice these assumptions and they remain hidden and non-obvious.
Ultimately I feel that current philosophy falls short of this promise. It either descends into technicalities or regresses to a prescriptive "this is how you should think" manual. Probably I am not well-read enough.
Once that is in place, philosophy can become much more valuable.
It doesn't seem to me that from this it follows that "the point of philosophy is better living". It might be obvious, but I just don't see it.
If there's any branch of human inquiry where no question is off limits then it's surely philosophy. Debate about the practical application of philosophy has been part of it's fabric for it's entire history. The Greeks certainly regarded it as something that should inform one's life choices and I'm pretty sure that is one of the main areas of focus in Existentialism.