Neuralink 'Participant 1' says his life has changed

Have there been any reviews by independent experts? This reads like a promo piece, in particular I'm not sure why the fluff bits about Musk "being a regular guy" are relevant. Most of the linked sources are either other Fortune puff pieces or Neuralink press releases.

Reviews by independent experts about the quality of this guy's life? I think he can be considered an authority on that subject.

so are people who claim placebos and homeopathy improved their conditions, we are not reliable on an individual level

You are right when it comes to qualia, but wholly incorrect in this case. There are measurable metrics in his life (ie independent use of computers, social engagements etc.)

It's not like he's having to rate his level of happiness here, these are physical benefits

Who is measuring the physical benefits? because based on this article it's no one... so again, we're taking one person's word for it... and it's very likely this person is contractually obligated to not disparage the company