Since jpg format is lossy compression, why is the camera output format still jpg format?

Due to the small file capacity of jpg format, it can reduce the pressure on the memory card and improve the storage speed (which is very important for high-speed continuous shooting). The image quality of jpg format has declined, but the difference is slight to the naked eye. Therefore, amateur cameras usually choose this format for output, while SLR cameras retain the original format (such as RAW format) output options, providing more post-processing space for professional photographers.

Just like MP3 format for music, although the sound quality of CD is better, you won't hear much difference unless you play it with a professional stereo, but the capacity of MP3 format is much smaller, which can greatly save storage space and facilitate network communication.