When I log in as user with
and try what I often do, namely start mc (midnight commander) then I get permission errors that the user (the application started by the user) is not allowed to create its configuration folder. I then I discovered that the user has no write permission there.
When this was consciously chosen for a important reason, then my suggestion is to have the home directory where is usually is at /home/username and there you can allow the user to write, without interfering with that important reason. With a symlink you could then bring /var/www/username in the home folder for convenience.