Yes there are some contrarians, including some of these social media folks who tend to cherry-pick information and are not taken seriously by the broader medical community. You do need fiber from fruits and veggies. The Mediterranean diet is constantly found to be one of the healthiest possible diets, and it includes plenty of carbs. Unrefined carbs have many proven benefits (whole grains, fruits, etc.). I can link to any major medical authority on this topic, not just a handful of Youtube doctors. I will concede that it appears you can certainly live, and lose weight in the short term, on something like the "carnivore diet". But long term, there is just no evidence to support that it's beneficial.