I always figured that to be able to call yourself a chef as opposed to a cook you needed some credentials and a history of performance. Turns out that all you need is a TV show and that famous doesn't equate to 'good'
https://upserve.com/restaurant-insider/famous-chefs/ This list of 'chef's includes the following (I put a star beside the only ones I'd agree were chefs). The order in which they were listed begs the question but then it is an entertainment oriented fluff piece.
Guy Fieri (really?)
Gordon Ramsay - yes! Even if his on-and-off blustering is tiresome
JJ Johnson - hadn't heard of him
Bobby Flay - yup, like his shows or not, he is a chef and a good one
Rachael Ray - really? (Don't get me started or it will be hard to stop!)
Sunny Anderson - I see her as an entertainer than can also cook
Wolfgang Puck - a solid chef before he ever thought of getting involved in the entertainment industry but I see him more and more now. I wonder how much cooking he, personally, still does but that could be said about any of the big time chefs, especially the ones that spin off into entertainment.
Masaharu Morimoto - excellent chef - really enjoyed him in the original Japanese version of Iron Chef. Take a look at this some time (on knife sharpening)
https://www.youtube.com/watch?v=h6dKczokYj8Carla Hall
Jamie Oliver - always figured that he was the British version of Graham Kerr, but maybe half as interesting.
Martha Stewart - cook - OK, entertaining - meh Chef..no.