I think you're throwing the baby out with the bathwater, while also pointing to the missing pieces in our understanding of the brain and consciousness.

I also work in the field, specifically with sleep slow-wave enhancement.

Blood flow as a proxy for brain activity I always felt was a weak measure, as the brain activity involved across all manner of operating our biological systems, so is the increased blood flow measured in fMRI a response to cognition, or autonomic activity? What does that oxydation mean.

EEG is similarly flawed when we try to equate "brainwaves" to emotions and consciousness. I think we're almost better off measuring HRV, a much simpler measure, and more reliable.

I'm fascinated that so many people who discuss brainwaves think of them as actual "waves", when it is just how we plot electrical activity which creates a visual wave like pattern.

However, and this is specifically related to our work in sleep, we can detect slow-waves (I dislike that term, it's the synchronous firing of neurons) and we are able to stimulate this restorative brain function through sensory perception during sleep, and even create slow-waves in a lab using TMS.

Research linked on our website [1]

I agree the industry needs to stop projecting what we hope we're seeing with what is actually being measured, and we don't understand enough about how the brain works, but I think completely throwing away any brain related measures we have is going too far.

1 - https://affectablesleep.com/how-it-works#research