In addition to what you wrote I see that this site have some illness.
Instead of creating normal modern wiki system it is used to post guides in form of posts which are hard to find. So they are really useless if compare them with ArchLinux Wiki or Gentoo Wiki previosly.
Also I do not see how this site helps to conduct communication between end-users and developers. Bugs are out of interest here, they are not discussed.
For newbies we have AskUbuntu, but it does not contain Canonical staff in the leader boards. So there is no communication between ordinary non-technical user and real developers. This is not the community anyway.
So Ubuntu community is dying and apply wrong decisions. I know at least two - the GNOME Shell is not really a desktop for enterprise users with 10-20 years formed habits, the Snap subsystem is excessive resource hungry and ineffective for both desktop and server markets.
So it is very difficult to predict how all this will affect real community and Ubuntu user base in future…