You don't own a movie on Netflix. But if you buy one digitally, which I have done, you can use it anytime, anywhere, on any device. It can't get lost, damaged, or stolen. And you don't have shelving full of plastic DVDs, VCRs or whatever.
My ebook doesn't really get dead batteries - it recharges like a phone but lasts twenty times longer, so it's not an issue - you can take it on vacation without a charger and have no problem. It's also waterproof (unlike a book) and while I haven't tried to smash it, I have dropped it any number of times, same as my phone, and it's pretty durable. But sure, you want to take care.
As for cost, it was about a hundred bucks, but ebooks are normally half-price or less, so I get that money back in a few months at most. Although books are downloaded onto it as well as being on the cloud, sure I am vulnerable to Amazon going out of business or something, though even there there are legal protections for digital property. Perpetuity isn't a thing for any media; what I want is things available to me for as long as I need them.
I find it hard to make a case for physical media except for the sheer pleasure that can come from them - I still buy physical copies of some RPG books, for example, because I enjoy the large format and having the art in my hands, but that's a subjective value. I think you can make an aesthetic argument for analog media, which will always be subjective. I think it is hard to make a strong objective argument. Digital media is more durable, cheaper, far less wasteful of resources, easier to store, convenient...
