Lots of people do it who should know better. That's going to damage the coating, shortening the lifespan of the pan, and putting little bits of Teflon into your food.
Out of the concerns above, pieces of Teflon in your food is fortunately not a huge concern: Teflon is not toxic in the slightest. It works as nonstick because it doesn’t really react with anything, and that means it won’t react with your body either. It is a common material in various medical equipment like implants, frequently used as catheter lining.
Now, if you heat it to 500 degrees or more, it starts decomposing, and the resulting chemicals are toxic. So, don’t broil in nonstick (but slow braising in oven is fine).
Also re oil, a great tip is to oil the food not the pan along with using nonstick too.
Oh, on that famous Pepin video (which is the one that taught me how to nail the texture), consider that Pepin probably has 100 pans a month sent to his agent/pobox unsolicited. He'd don't give a crap about that pan lol.
Cast iron is great for searing or for fried eggs or buttery scrambles.
I love my car on steel Matfer fry pan and try to use it as often as possible.
But for acidic or long simmering brown sauces that'll stick and tear off my seasoning, I'll probably teach for stainless steel. Afterward I'll scrape it down and it's good as new.
Nonstick has its purpose. One that I rediscovered recently is very low fat pan frying. Even though all my steel/iron pans are well seasoned, I still need more butter or avocado/grapeseed/coconut/etc oil when compared to cooking on a Teflon pan. If you are trying to cut calories, you'll need to count the additional cooking oil that goes into your carbon steel or cast iron dishes.
Yes, I am aware of the benefits of good fats in my diet. But sometimes you want to track or reduce total kcal consumption, e.g., if you are a weightlifter but aren't currently bulking. Reducing fat intake is the easiest lever, since you want to keep protein intake high, and want to limit carbs.
So yeah. Use the tool you enjoy using. I've seen Chef Jacques Pépin beat an omelette in a Teflon pan with a metal utensil, so who am I to judge???
Non-stick : JavaScript / Python
Cast Iron : C
Carbon Steel : Go
Stainless Steel : Java