The vegan & vegetarian diets are not suitable for everyone.
Take me, for example.
I'm a type 1 diabetic.
I have to watch my carb intake.
The aforementioned diets are fairly to very restrictive, & obviously, because of the lessened protein, carbohydrate takes priority.
In diabetes, too much carbohydrate can lead to high sugar levels. Prolonged high sugar levels can lead to limb loss, organ failure, blindness & eventually, a horrible, painful death.
For me & millions of others, an omnivorous diet is key.
Also, have you thought of third world countries? Due to their extreme weather, access to foods for restrictive diets isn't always possible.
If crops fail, slaughtering a goat might be the only way to feed families. Insects too provide a nutritional boost for many.
Yes, it's sad of their suffering, but the food chain says otherwise.
If people are healthy & have access to foods to maintain their restrictive diets, that's great.
But it's not for everyone.