Think of it like being a cook in a restaurant. The order comes in. The cook plans the steps to complete the task of preparing all the elements for a dish. The cook sears the steak and puts it in the broiler. The cook doesn't stop and wait for the steak to finish before continuing. Rather the cook works on other problems and tasks before returning to observe the steak. If the steak isn't finished the cook will return it to the broiler for more cooking. Otherwise the cook will finish the process of plating the steak with sides and garnishes.
The LLM is like the oven, a tool. Maybe grating cheese with a food processor is a better analogy. You could grate the cheese by hand or put the cheese into the food processor port in order to clean up, grab other items from the refrigerator, plan the steps for the next food item to prepare. This is the better analogy because grating cheese could be done by hand and maybe does have a better quality but if it is going into a sauce the grain quality doesn't matter so several minutes are saved by using a food processor which frees up the cook's time while working.
Professional cooks multitask using tools in parallel. Maybe coding will move away from being a linear task writing one line of code at a time.