There is no such thing as a carb being a necessary nutrient, they simply arent
Carbs aren't nutriets, just a different type of fuel. Much like water can be solid, liquid or gas....all glucose comes from carbs, proteins or oils. Carbs being the quickest way for the body to get fuel.
There were some recent studies which suggested that carbs are needed for the body to properly assimilate certain vitamins. There is no exercise guru/top-athelete on the planet who is against carbs.
I agree with the video where doctors cured type2 with starches and simple sugars. I've read on that years ago and makes sense.
The waters get murky when you start to demonize all oils, as that is the same extreme position of demonizing all carbs. I think omega6/processed oils are the main issue. They are the ones which block the insulin receptors. Omega6s are everywhere, and omega3 oils are hard to get.
The other murky issue is high-fructose corn syrup which is NOT SUGAR and horrible for your pancreas and liver. If one were to eat a "high carb" diet and not avoid corn syrup, they'd be doing a horrible thing to their body.
In summary, due to all the processing of our foods, a healthy diet is hard to achieve. And also, most foods are devoid of nutrients, whether you're talking about fats or carbs.
Some people seems to operate better on keto vs high-carb. I've seen plenty of amazing atheletes who are high-carb/ even vegan. I really don't think there's a one-size answer.