For cellphone and camera manufacturers, App developers and test labs it is very helpful to know how cameras are used. Under which lighting conditions are images captured? What is captured? Was the flash used? Many more things can be analyzed by looking at the image content and the metadata. The last analysis dates 9 years back to a time when smart phones with integrated cameras started to take off. Since then a lot of the usage conditions of image capture devices have changed. People don't use the flashes anymore, they take a lot more pictures of food than before and a lot of the images are selfies that did not exist. Knowing how a camera is used can help prioritize certain developments, allows to optimize algorithms for image processing and can help archiving images in better ways.
Dietmar Wueller, Reiner Fageth, " Statistic analysis of millions of digital photos 2017 " in Proc. IS&T Int’l. Symp. on Electronic Imaging: Photography, Mobile, and Immersive Imaging, 2018, pp 344-1 - 344-4, https://doi.org/10.2352/ISSN.2470-1173.2018.05.PMII-344