This question has an answer by "user11357", whose name is grayed out and cannot be clicked on.
What does that mean? Was the user banned?
That is the leftovers of a user that no longer exists. When user accounts are removed, their content remains and the system reverts the display name to a generic
The reason for account removal can vary and could be a voluntary request or a result of their actions on the site but the specifics are not publicly available. It is enough to know that whoever they were they are no longer contributing to the site, but past contributions remain.
It's not the case with the question you refer to, but greyed-out usernames can also be the result of a question being migrated from one site to another. When that happens, any users involved that don't have accounts on the destination site get greyed-out "placeholder accounts".