Gentle reminder that RAID is not backup. Have at least three copies or backups of important files preferably in different locations.
And keeping things on your own drives has its caveats - I work in IT and have seen data loss from sprinkler systems raining down on server closets, leaky AC units, no ability to access email and data for days and weeks due to Hurricane Sandy, and battery backups with dead batteries causing RAID corruption upon power loss, and more.
With that said, your points are good ones and things will inevitably get lost - over the past few years I've plugged in old drives and floppies from the late 90s and old burned CDs from the 00's, some of which have already started decaying, losing unknown files. We are creating so many files and documents that we value but others likely won't. I rest a little easier knowing I still have documents from university, but my children probably won't care or ever want to read my 25 page final paper for my "Civil War" history class or my first Java program (make an elevator!).