But that's the brilliance of the Apple ecosystem...it's all there in iPhoto. I don't have photos in various folders scattered hither and yon, they are all in one place and when I move to a new Mac, they will all come with me, as they have in my previous 3 platform moves.
I don't think it's a big IF at all. There is always someone in the family willing to be the caretaker of the past, those photo albums are sitting in someone's attic right now or on the shelf of the spare bedroom. In the future, sure, those albums are easily accessed, but no one may know who those people are or where the pics were taken. Which is not a problem with my photos in iPhoto.
My cousin from the other side of the country sent me multiple photos of my grandparents and grand-aunts and other family member pics for the 40s-70s that I would never had access to otherwise. There are SO many pictures of us and out family members locked up in other people's photo albums in their homes. I'm very thankful for the digital revolution, since we are finally getting to share these old pics that may be important to a few people, but were segregated due to the inability for us to have copies of said pics. I actually thank FaceBook for a lot of this which has allowed me and friends and family to share old picture I would otherwise have not gotten a chance to see.
I think it will only get easier over the next decade or two to store our files electronically. Right now, for solid backups or pics and video, we admittedly jump through a lot of hoops. Once cloud storage is popular and the norm and everyone has internet access speeds 10-100 times what we have today, we will look back on this quaintly and laugh at the multiple backups and all the work we did and how much local storage we all thought we needed.
Sure, a photo album will survive better than electronic impulses on a magnetic medium. But at least in my situation with two children and many other family members who are extremely interested in family history, I have no doubt our pictures and videos will survive.