Their point was that (i) React becoming the defacto standard played into the hands of Meta, who are interested in tracking people. (ii) Tracking is made easier by running arbitrary JavaScript in the browser. And (iii) before SPAs were big (pre-React), more people used to completely disable JS in their browser.

Not saying I buy this theory. Just trying to explain what I think they were alluding to, as I had the impression you missed it and went in a different direction.