I think the reason why materialism is the default today, is because of the idiom, the metaphor, we use to describe reality.
Metaphors have a tenor and a vehicle: As in sausage dog, the vehicle is a sausage, and the tenor is the implied value that it shares with the dog. Ever since the Enlightenment and perhaps a bit earlier from Descartes, we have mostly used a mechanical metaphor - even Christians like Paley with his watch use them - and Industrialisation accelerated it. We talk about the function or mechanism of something; we call the heart a pump; we say something is systematic. The vehicle is obviously derived from machines, and the tenor is clear.
But now we reverse the metaphor, and confuse tenor for vehicle, as if a dog was really a sausage. The heart is not really a pump, say, and the most notable example of recent years is the brain. We first used the metaphor of our 'thinking' and 'learning' to describe what a computer does - now it is taken for granted this is what is happening, and we reverse the process to treat our brain as a computer, albeit a living organic one. Our metaphor is running amok, and because people no longer realise they are metaphors, they assume it a real value - the vehicle is disappearing, leaving only the tenor (such as happened with other metaphors like understand, literally to stand underneath something; or disappoint, literally to not be picked). If all your language is to describe things mechanistically, as in the rotation of the sun (from a wheel) or so, is it any surprise people assume a clockwork universe? All you need is introduce automaticity, to remove the Prime Mover or Watchmaker, and there you go.
@Jok with the brain, this connecting it to chips and transplanting bits of it, is also mechanical metaphor. The brain does not use circuitry, but axonal impulses are one way depolarisations across nerve membranes. It is electro-chemical, but it certainly is not amenable to computers - which at heart are merely 1s and 0s in multiples of circuits being on or off. A brain-machine interface would of necessity be a stimulus that the brain somehow receives therefore, a changeover of type of activity would have to occur at the quick. Integration of brain and computer is quite implausible actually, but people think it reasonable because of our metaphor. Just how we pretend computers think or learn, when really they are running programmed functions or algorithms that are mere extensions of such programming, which by repetition can attempt to achieve a desired programmed end-point by various mechanisms, and we can then judge which most closely aligned with the goal. Now we are facing an increasimg belief that algorithms will save us, that computer simulations will 'learn' the best way - and it is more and more being implemented, a blind mechanism enforced onto organic reality, in a macabre reversal of metaphor like the Saracen Head in Hideous Strength.
The brain is an organ, and people forget that organ and organic means something that is separate but cannot be removed from the whole. It is interconnected with the rest, and the brain both acts on, and in turn is influenced by, every other organ system. We are not just our brains riding around a meat car, which is just further mechanical metaphor confusion, but the organic whole. How that whole is related to mind, is another problem, but more than just the nervous system is at play here. Personally, I do not think the mind/body problem is reducible to either side, and computer chips or so won't change this - as functionally we already have a brain interface with cochlear implants for hearing loss, and no diminishment of person is brought thereby, quite the opposite.
Basically I feel we are being silly, and it is this felt alienation of mind from matter that causes this. The mind is of matter, surely, as the neural correlates for consciousness seem to say, but it is also not. Those 'parts' cannot be readily divided, nor do I think they can really be (hence the idea that we receive glorified bodies at the Parousia makes exquisite sense), so I think we have something akin to the Incarnation - to borrow the metaphor, something fully spiritual and fully material, indivisible hypostasis.