I don't have the server space to store gigabytes of photos. And do the security checks to avoid porn and lewd photos from being uploaded.
Then if you offer your own storage, you get into potential copyright issues by hosting and using someone else's photos. Probably not a problem in 99% of those offering photos to this site. But then one weirdo surfaces.
I wonder what the annual cost is for you to have the necessary server g/b's?
Other sites use member policing and feedback to control spam and porn. Could that work here?
Is liability insurance available, and at what cost to protect you against copyright issues?