Google Photos allows unlimited storage. As long as you elect to store the photos/videos at a slightly lesser quality. Which they still look great when browsing them.
Because of this, I've been able to index over 43,000 photos/videos of our family from the past 10 years. I tracked down every old laptop, phone, and external drive I could find, and grabbed the photos off of them to have them in one consolidated place.
With Facebook, you can even export your photos from FB to Google Photos directly. Here's the link:
Births, our wedding, soccer games, Christmas's, it's all there.
I'm hoping that the service lasts longer than my lifetime. :) And that I can pass down the URL to my kids.
P.S. The search for Google Photos is amazing - it recognizes faces, locations, events (e.g. concerts, weddings, etc), and even objects (e.g. red dress). It's everything that iOS Photos should be.