How profitable are street stall business? | Proxies-free

I have seen in TV that there are many people who have like stalls in some busy street. And they tend to make a profit during the busy days. I am not sure how hectic and tiring that is. As in working in the cold and the sunny days out open. It can be bad for health with all the pollution as well. However considering those stalls do make a profit after certain time, it can be worth trying out. It seems ready to eat food, vegetables, plastic items can be sold for some profit. And there seems to be demand for such in the open street.

Do you have any experience in this niche? Have you tried such business?