A couple of years ago I realized how much 'stuff' I've got online and I wouldn't want it to lie fallow should I not be able to continue producing content (sick or dead, basically). Google has addressed this issue and not only are you able to download and archive all of your own stuff stored with Google, but you can assign someone (or several someones) the capability of downloading some or all of your data. The Inactive Account Manager Page walks you through it.
It's not something we like to think about, but when you get it done, there's a definite sense of relief.
Go to Google's My Account page to get started managing your online presence and get everything the way you want it. At any time you can download your data, all of it. You can stay with Google or leave. I love choices.