Those 6 Gb come out of nowhere. The article does explain the reasons for remote installation quite well.
The ability to install the system over RDP and VNC existed for quite some time, and is used by many. Now WebUi allows us to significantly reduce the requirements for this use case, and have all the expected features (like copy-paste) work much easier than it is done with the remote desktop tools.
And of course the text mode, and kickstart installations for Anaconda, stay no matter the choices and features of the graphical UI.
You need to add much more context and details in your comment, if you’d like to turn this into a meaningful statement.