Before browsers screamed bloody murder over http, a MITM could defeat SSL by acting as the SSL endpoint and forwarding everything as plain http. And back then, the only indication was lack of a 16px lock icon and a missing "s" in "https".
It's additionally daft to think that just because the page is public knowledge, a specific person reading the page is never sensitive information. As a blunt example, Wikipedia is obviously public knowledge. If you are a Chinese national reading https://en.wikipedia.org/wiki/1989_Tiananmen_Square_protests... then the CCP might like to know your location.
As explained in the article, using HTTPS provides very little protection against whoever operates the site to which you are connecting, who might still not be who you think they are, despite accepted certificates.
Nevertheless, using HTTPS, especially when not transmitting any non-encrypted information, like the name of the site for which the connection is requested, protects you from those third parties who are not able to intercept your outgoing connections and act as middlemen, but who might still monitor your traffic and attempt to record it or to interfere with it.
Of his complaints about misguided security, this one has resonated the most with my experience:
"Regarding my new enemy, ...
• The absolute shits that have locked down corporate computers with the assumption that the user can’t have a legitimate reason to change settings on it, put in a USB stick, use the command line, run an “untrusted” application like emacs or something that I just wrote and compiled myself, or basically any application other than a web browser, even if that user has been programming for 40 years and has a Ph.D. in computer science and was hired for that very experience."
The result of being given this kind of corporate laptops is that I have never done any kind of work on them, but I have kept them open on my desk just for reading my e-mail messages in Exchange, or for using Teams and the like, while doing all the work that I had to do on my own device, over which I had the control needed for productive work.