No, that is not a good way to hide a field. Not returning the field from the filter is causing several PHP errors that you’re probably not seeing.
There isn’t any way using PHP or filters that will let you hide an individual field based on the current user.
If you want to have fields that that user can see and separate fields that only an admin can see then create 2 field groups. Put the fields the user is allowed to edit in the first and set the second field group’s location rules to only allow it to display based on the current user’s role.
