Indeed, this is something not discussed in an otherwise very good article.

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.