Yes, I think the general consensus is that consciousness is a spectrum. But even when something is a spectrum, it can still make sense to define a binary in ter

Yes, I think the general consensus is that consciousness is a spectrum. But even when something is a spectrum, it can still make sense to define a binary in terms of a threshold, like how we define bits in terms of high and low voltages. Obviously even when you're on autopilot you're above a certain threshold of sentience because you're still having conscious experiences. You would react if you were to see something dangerous or feel something painful. I still think it makes sense in this context to say that humans are sentient most of the time. I think it's reasonable to assume that intelligence is orthogonal to consciousness. I can imagine an AI that is very intelligent but has no subjective experience. Similarly, I can imagine a creature that has a very rich range of subjective experiences, but is unable to understand and change the world around it. Obviously these are just thought experiments and we don't have good theories of what consciousness and intelligence really are, but I think it's consistent with our current understanding of biology and neuroscience.