Google Chrome version 69 no longer shows the ‘m.’ and ‘www.’ subdomains in the address bar. According to the developers, this subdomain is ‘insignificant’ and thus superfluous, but certainly with ‘m.’ there is an essential difference in where the user ends up.
In a discussion post on the Chromium forum, users are fighting hard against the change. An answerer, who says he works for an internet provider, calls the change stupid. This is because the presence or absence of ‘www.’ in some cases leads to a two different destinations. Of course that also applies to ‘m.’ Good examples are tumblr.com and m.tumblr.com ; these are two different sites that now look exactly the same in the address bar.
Another respondent points out that the system can behave strangely. The example url ‘subdomain.www.domain.com’ changes to ‘subdomain.domain.com’. Even when the ‘trivial’ subdomain is in the middle of a url, it is removed. A developer does acknowledge that this is a bug that needs to be corrected.
Google recently indicated earlier that it no longer wants to display the URL in Chrome in the future. Addresses would have become too complicated, which could confuse users and make them vulnerable to maliciously manipulated URLs. Google wants to fight this, but without it becoming unclear on which site a user sits. However, this change makes it less clear where a user is located.