Sad to say he's right. I once tried to look up academic work on these issues and found essentially none. Almost all you can find is loosely disguised white papers from the manufacturers of "ergonomic" tat.
I never used or wanted an "ergonomic" keyboard but have used all sorts of keyboards over the last four+ decades, from high force mechanical to apple "butterfly" and apart from membrane keyboards they all work the same for me. I credit my late piano teacher for that.
As for chairs: the Aeron is more work than it's worth to me and I used one only because my wife bought it for me. But there's a secret that doesn't apply to everyone: in body size/shape/configuration I'm right in the middle of the bell curve (5'11", BMI of 22, etc). So stuff "out of the box" (car seats, airplane seats, computer desks, etc etc) is designed for me. This was famously a problem for military aircraft in the 40s (cockpits designed for the norm); learning from that inversely affected the choice of early astronauts (nobody too tall or too short or with arms too far out of norm simplified the UX). Also I apparently can stretch and even go get more tea without losing 'flow'.
So yes, chairs work for me but there's a lot of variation. Too bad these expensive chairs don't help.
> Herman Miller who invented the office cubicle: the second most dystopian form of office,...
The irony was that the cubicle was designed as a tool of liberation: until then all work areas, in factories and white collar work were open plan like today (just look at a 1950s movie like "The Apartment"). Finally the cubicle could give workers some modicum of privacy at a cost lower (and flexibility higher) than building lots of private offices. Sad it because a soulless dystopia and was replaced by...open plan offices.