Yes, there are unfortunately many thousands of old observations that now lack photo evidence because the link to Picasa, Flickr, or Facebook was changed or the photo was deleted on the external website. All photos should be stored locally on iNat.
@j-k is this a feature request, bug report, or just a #general discussion? (currently it’s placed in Bug Reports, but I’m trying to find the actionable bug here that isn’t already represented in a different report, like the blank images being added in the Photos gallery on Pixel phones). Thanks!