I am downloading a lot of photos to my public tree. How safe are these as a repository for future generations? What happens to my tree once I die?

I remember keeping my photos on an internet sharing site once that folded. I lost all of my photos.

This is sometheing I wonder about.

It would be good if family trees and other records could be stored for future generations. Imagine if someone is looking for the same relatives say 100 years from now.