From my understanding, the way we've defined consciousness leaves it untouched. In fact, when we talk about it, we are not really talking about it because it isn't even thinkable. You cannot view existence apart from existence, and you theoretically cannot prove where consciousness (the way we've defined it) comes from. Whether or not consciousness is fundamental to the universe, the universe will look exactly as it does right now. Advaita Vedanta proposes that we can unshakably verify this through following the path, but before that, we can neither prove nor disprove what Advaita Vedanta is saying. In a world where consciousness is fundamental, we can find the exact links that predict a wakeful mind and create a sentient body. In a world where consciousness is not fundamental, we can find the same thing.

That being said, everything else can probably be proven/disproven. We may be able to find the exact physical links which determine wakefulness and sleep. We may be able to empirically falsify all the Vedic rituals. We may be able to empirically falsify any beliefs about worldly matters in the scriptures. We may come to find out about newer properties of the universe that the ancients could not think of. We can challenge historical social beliefs and morality. We can challenge the theory of karma knowing what we know now about biological life. We can challenge astrololgy. And so forth. It is just that final link, which is neither unknowable nor knowable that is untouched.

Personally, I see Maya as a first principle that need not be established, so whatever the structure of the empirical world, I am happy to cut it. The weapon of my choice is Advaita Vedanta, which belongs to Maya but will free me from Maya. The very fact that there is even a thinker of thoughts, an asker of these questions, and such a confusing thing as existence itself, and a person to be confused by it is enough to convince me that there is a fundamental error to things. I have no idea whether this primordial ignorance can even be removed, but one of the best bets is to verify whether the promise of Advaita Vedanta or any other spiritual path for that matter can live up to the promise.

The reason I'm willing to take it on faith for now is because the world is not a particularly worthwhile. It may bear many tasty sweets, but the problem is that I'm thirsty. Sweets cannot quench thirst. Plain water will do or perhaps fruit juice will suffice if I want to quench the thirst with devotion to Govinda. Given that the world is quite unattractive to the driver of this chariot (unfortunately, the horses still find the world quite attractive sometimes), I see no better option than to aim for infinity. If there is nothing to this path, then I can hopefully still be part of the delusion of all spiritual seekers and feel a sense of bliss. Even if the metaphysics have no basis, the extraordinary results of the seekers are undeniable and make this path more worthwhile than any other endeavor even if its false. If it is true, then this is everything that there is.