The topic itself might be easy to answer, but I do feel that it is not that simple and there is no single right answer either.
For example, the data (pictures, videos etc) might have value for the younger generation, but if you encrypt it, those will be gone after you are away. I know that that is a far fetched topic, but still valid. I think that one big question is that how do you document all the places where your data is stored an in which format for the younger generation, so that they can access it and know it that it is there.
For the physical devices, like the old disks, the weak point has been the controller boards, and for the floppies, I must have stored them in near speakers etc. CD's and DVD's must have gotten too much UV radiation from the Sun. Once I did try to keep up with the storage media wars, but it was too time consuming and error prone as well. And I did have setup offsite backup, but the upload bandwidth was too narrow to handle the huge data uploads, some days 32-64GB of raw images.
During the years I have been thinking that maybe it would make sense more to develop some kind of software to provide data to paper conversion, such as High Capacity Color Barcodes. Then I could just write a software which would convert the data into raw photo files and then ask the some shop to print them on some real photograph paper. This way the data would be accessible for the next generation and it would be kept private, while the source code and technical papers would be made available as open source. But having something like that might not be doable right now, giving that the resolution which the images can have might not be good enough to store more than few 100kb per image. But it would be good enough for storing some source code. Does this sound like a good idea? As if it does I could start to work on it on GitHub on my spare time.
For this I did do one experiment few years ago, where I was checking how fast I could transfer data using barcodes. I made a software which was synchronizing data between mobile phone and desktop without any cables or wireless connections. It was just using the display and the camera. The funny part for that is that the laptop failed and the data was lost, but the idea was simple and it worked.
But I do thank you for your time and I feel a lot better knowing that I am not the only one puzzled by this long term data storage issue.