Someone who is bad at what they do, someone who really doesn't know what they're talking about, but they do it in a way that seems outwardly proffessional.
Adjective form: proffessionally-incompetent
It Doug has so much professional-incompetence, he posts his own drivers-ed tutorials online, but he doesn't even know how to drive.
Sarah is professionally-incompetent, because she really does look like she knows what she is talking about, but the pros mock her, because to an outsider she looks like she can talk the talk AND walk the walk, but her catwalk is not a real catwalk; she would hurt herself on a real catwalk.
A intellectually incompetent incel or a "III" is someone who is stupid as shit, and still has a v-card.
Intellectually incompetent incel
When there is a task or job function that you consistently screw up so the organization assigns the task to someone else, this rewarding the incompetence with lower responsibility.
Jim was responsible for printing and applying the labels to the shipping boxes, but kept putting the wrong labels on, so it is now his supervisors responsibility. Thus Jim has received rewarded incompetence with lower responsibility.
to be an incompetent loaf means to have a serious lack of intelligence or smarts in any sense of the word whilst sitting limply and letting anyone slice, dice, or dip your lack of skills into their bowl of repeated insults...per their own pleasure and satisfaction
I'm am sick of my boss thinking I am an incompetent loaf who can do nothing but simplistic data entry!
A collective name for the highways agency in the United Kingdom
5 sets of roadworks in 30 miles? Who thought that was a good idea? Oh, of course, those criminally incompetent fuckwits at the highways agency