Two huge reasons to use stock photos for your projects instead of hiring a photographer or spending hours making them yourself: Save Time & Money!
Time and money are not everything, but they are huge when you are just starting out and are super busy.
Using stock photos for your projects instead of hiring a photographer to shoot photos for you save time: stock photos are already created, post-edited and ready to be downloaded and used. They also save you money because the equipment, lighting accessories, the editing software are all huge investments and often take years to learn.