Literally just mainlining marketing material straight into whatever’s left of their rotting brains.
here's the task of people that want to prove that the human brain is a meat computer: Explain, in exact detail, how (i.e. the procsses by which) Qualia, (i.e. internal, subjective, mental experiences) arise from external, objective, physical phenomena.
hint: you can't.
Why not? I understand that we cannot, at this particular moment, explain every step of the process and how every cause translates to an effect until you have consciousness, but we can point at the results of observation and study and less complex systems we understand the workings of better and say that it's most likely that the human brain functions in the same way, and these processes produce Qualia.
It's not absolute proof, but there's nothing wrong with just saying that from what we understand, this is the most likely explanation.
Unless I'm misunderstanding what you're saying here, why is the idea that it can't be done the takeaway rather than it will take a long time for us to be able to say whether or not it's possible?
and the usual neuroscience task of merely correlating internal experiences to external brain activity measurements will fundamentally and definitionally never be able to prove causation, even hypothetically.
Once you believe you understand exactly what external brain activity leads to particular internal experiences, you could surely prove it experimentally by building a system where you can induce that activity and seeing if the system can report back the expected experience (though this might not be possible to do ethically).
As a final point, surely your own argument above about an illusion requiring an observer rules out concluding anything along the lines of point 2?