What is the main advantage of a mirrorless camera?

The main advantage of a mirrorless camera lies in its design, which lacks a mirror reflex system that is typical in DSLR cameras. This absence of a mirror mechanism allows mirrorless cameras to be significantly smaller and lighter. Photographers often appreciate this portability, especially when it's crucial to carry equipment for extended periods or in varied locations. Additionally, the streamlined design can contribute to a more compact lens system, making it easier to pack and transport.

While other factors, such as sensor size, optical viewfinders, and film use may play roles in camera performance and capabilities, they do not define the essential benefit that mirrorless technology offers over traditional DSLRs in terms of weight and size.