> Why is the round bottom so essential that without it we can't call it a wok?
you need the round bottom to be able to scoop up the food and churn it. Try using a spatula on a flat bottom "wok" and flip the food to churn it - it doesn't work very well.
There's also an edge between the flat bottom and the round sides. This causes food to get "stuck" there under high heat - leading to burning. A wok is round all the way, so the spatula scrapes everywhere evenly, and you leave no burnt bits.
A flat bottom "wok" is just a pan with high edges.
you need the round bottom to be able to scoop up the food and churn it. Try using a spatula on a flat bottom "wok" and flip the food to churn it - it doesn't work very well.
There's also an edge between the flat bottom and the round sides. This causes food to get "stuck" there under high heat - leading to burning. A wok is round all the way, so the spatula scrapes everywhere evenly, and you leave no burnt bits.
A flat bottom "wok" is just a pan with high edges.