There are times when catering is optional. A person may or may not choose to cater a house party. It really depends on the number of guests that are expected.
Small intimate settings do not require a lot of effort. Snacks and finger foods may be fine for these times. There are other times when a big crowd is expected. It may be a birthday or a bridal shower. It could be a celebration for a graduation or a job promotion. All of these events would probably bring a large crowd.
It would be beneficial to the host if their time is limited. It is often easier to hire caterers. More info: catering Fredericksburg