confident but superficial and shallow
glib - shallow
The word ‘glib’ is used to describe speech that sounds good but lacks depth and meaning, or a speaker who says something in an authoritative way, but without careful thought or honesty. It is used as a means of expressing disapproval, and is frequently associated with people such as politicians and salespeople.
The job interviewer didn’t seem too impressed when I was telling her about my leadership abilities. I think she thought I was being quite glib.
I believe Anne should have been arguing for strong reforms rather than glibly calling for the whole department to be abolished.
John wants to get out of sales. He’s sick of the glibness and superficiality that comes along with it.