Back in the day, when being a cable cutter was a badge of a pioneer - I have to admit that in all the excitement I never realized that switching to streaming digital content means never having access* to “your collection” - available catalog always changes. Doesn’t matter how old the content is - someone is always busy thinking of a ways to monetize it, which usually translates to it not being available when you want to watch it.
I haven't cut off all "digital streaming" but I personally definitely bucket things into "things I may want to see later" versus things I don't. Some things are just intrinsically disposable content, e.g., once you've seen Survivor Season X, you're probably not going to watch it again. (And, if you are one of the people for whom that is not the case, well, by all means, change your personal categorization, rather than arguing with me.)
I still buy things I may want to see again. And since I'm still using DVDs I bought 20 years ago, I know that that can happen. Many of them are simply not available on streaming. Others are, but would involving chasing subscriptions hither and yon, and more than once I've done that, only for the content to not actually be there when I finally got to wanting it.
Also, I will say, music I am still buying. Purchasing MP3s is acceptable, if anyone will sell them to me, but I want to own anything I really care about. For any given CD I have no real confidence that anything but my physical possession (converted to MP3 and backed up) will still be there in 20 years.
* unless one blackbeards it