What is the difference between photos on a crashed harddrive, and photos in a shoebox that that just burned in a house fire? Photos are vulnerable to many different attacks just like digital data.

These days your photos are probably backed up by facebook, google, or are such major players. (there are a lot of privacy concerns with the above, but they do tend to have good backups)

There is a lot of serendipitous backing up with social media. There was also a lot of serendipitous passing on to relatives of physical media. Not sure which better stands the test of time. (And I'm sure it varies.)

Often passing on to relatives is done with the only copy (well you retain the negative). School pictures come in packages of many, but otherwise you typically only print one copy.