Usually in the creative space when it comes to photos and videos it is common practice for the artist to simply give the client deliverables of the work. For example, if a photographer takes a photo they give you the final edited images as the work versus giving you the RAW original file of the photo that was taken with the camera. Same for videographers where if they captured video of an event they would offer the client an edited video of it versus the original footage captured.
It’s most for business and copyright reasons where giving your original source file enables the client the full ability to modify and reuse your work which is not something people would want to do. It’s different if you were say hired to work on a film set where you are just the labor using the production’s equipment. But in these cases where one is using their own equipment and all it does seem like one is being taken advantage of.
They are basically getting free rent for the gear you are using too when you think about it. On top of them wanting to eliminated the need of having to use the person’s service again. In my opinion, it’s not worth it in those cases. It’s hard of course if you are desperately looking for work. But it will cost you more in the long run.