There could be two ways of answering this question…being a street food junkie, I’ll be more than happy to address it from both angles.
‘Why do we have street food?’ as in “What is the need for street food to even exist?“
This is because not everyone has the finance nor the resources to start a full-fledged restaurant. And if he is going to make only limited dishes, it’s going to be even more difficult to maintain a restaurant with only 2 or 3 items. Plus you have the additional headaches of obtaining licenses, certificates, regular checking by food inspectors, etc. All the guy needs is some basic stuff like cooking ingredients, a cooker, and some utensils. And sometimes he doesn’t even need a cooker!
All of this may be set up even on a little kiosk or a makeshift arrangement. The food is prepared on made-to-order basis right in front of us and it is as fresh as it can possibly get.
‘Why do we have street food?’ as in “What is the reason for people having street food?“
Because it’s delicious, it’s quick and you need not be worried if the food being brought to you from the kitchen was made with rotten tomatoes or other expired stuff. Hot and happening. That’s what it is 😀