Legally, due to copyright, none of us really own the movies, books, games, etc. that we buy. But when we buy it on physical media, we have more control over access. Even then, there's attempts to limit our control. Blu-Ray and DVD both have region coding, Blu-Ray has DRM built in to the system, and if those seem a bit much, I'd like to at least be thankful DIVX crashed and burned. One of the things we need to think about, when we think about ownership, accessibility, etc., is that physical formats don't last forever. Everything from magnetic tape and magnetic drives to optical disks to paper all have a limited life span. Similarly, in regards to electric media, the devices that can run these formats also have a limited life span. So while we might own a physical game or movie, copy isn't going to last forever and I think it's important to consider if, how, and when we might be able to access it again down the road. As an aside, there are some great YouTube Channels like Techmoan that go over all sorts of obscure formats and their history. Recently, due to the merger of AT&T and Time Warner, Filmstruck was closed down and with it, people lost easy access to classic, rare, unique, and fringe cinema. Many of those films are hard to find and if and when they'll be easily accessible again is anyone's guess. In some ways, it reminds me of how the majority of silent films were lost just because studios didn't perceive them as valuable and as a result, thought it was more prudent to destroy their copies than to store and preserve them. I'm not saying that AT&T is going to destroy all of their copies of various films, just that businesses tend to worry more about what makes business sense first and cultural value is often an after thought. All of that said, the more I tend to think about this subject and similar subjects, the more I see the value in concepts like public domain and creative commons, creating our own culture through crafts and hobbies instead of relying on corporations and businesses to provide us culture, and most importantly, enjoying and appreciating what we have while we have it, because for one reason or another, what's here today isn't in any way guaranteed to be here tomorrow.
I think those are all good points, although the way copyright law works with this stuff (at least in the U.S.) is a tad more nuanced. But your underlying statements stand. Tangential example of the technology change thing. We have gobs of pictures and videos of my daughter from over the years. What's the best way to back them up? Obviously off-site is key, for one, so that we don't lose everything should e.g. a fire happen. But changing formats and what-not has been a concern. Admittedly, image encoding has remained pretty stable over the years. My original plan was to use M-DISC blu-rays, and put them in my safe deposit box. But I'd have to (1) trust the maker's claims about their longevity, and (2) put the portable burner I'd have to buy in there with them and hope that they're still usable down the road. My current plan is to use Amazon Glacier and just put everything in an encrypted file container. Some of the same risks are involved, but I'm hoping they're lessened that way.
Oh, I'll readily admit that I'm painting in pretty broad strokes. Each of those paragraphs could stand to be a whole, in depth conversation. As for archiving stuff digitally, whether they're along the lines of family heirlooms or more "official" stuff like legal records for businesses and such, I remember reading an article years and years ago about people wringing their hands and pulling their hair trying to figure out the way to back stuff up. There were all of these issues of not only competing types of media, but competing file formats, codecs, software, and operating systems and the whole struggle of trying to figure out what to do with ever changing formats, dying formats, and incompatibility. I think finally, we're we'll pass that in so many ways. Partly because standards have condensed, for instance digital cameras mostly use SD cards these days, instead of SD versus xD, versus Pro Duo, versus Compact Flash, but also because so many different programs can read more than one type of file and one type of file can be opened by so many different programs. Not only that, but even compare to a decade ago, storage space is so cheap today. That was the hard stuff, and now that's out of the way, like you're saying, more practical concerns like file quality, bit rot, and ease of access are really what we mostly have to be concerned with tackling. Edit: Speaking of backing stuff up, I heard a member of this organization give an interview on the radio one time and while I think what they're doing isn't all that practical, listening to him talk was interesting because intentionally or not, his ideas and his projects were very philosophical in terms of why we desire so step fly to preserve knowledge and the lengths we're willing to go to do it.