When the CD was still relatively new, Steve Albini of Big Black dubbed it "the rich man's eight track". I giggled at that sobriquet, because the popularity of the format, even with indie record companies, was its own refutation of such a snarky label.
Now, I giggle a little less. The compact disc has become something of a historical curiosity, although less because of actual technological obsolescence than because people simply find downloads more convenient than ripping. The massive gains in convenience for downloads trumped the loss in sound quality — minimal for most people, anyway. (Most of the music I care about is either only on CD anyway, or only worth hearing with as few compression artifacts as possible.)
Two other markets are hanging on to physical media for dear life. One is publishing, where paper books still offer some things their digital counterparts cannot, and most likely always will. The other is high-end home video. To wit: Warner Brothers has just thrown its hat into the 4k video ring with a slew of first titles for that format.
Most every new home video format debuts with a list of titles that is a mix of whatever is hot and current, along with a couple of guaranteed catalog titles. In this case, the current hits include things like The LEGO Movie, and Man of Steel. It's not like I'm about to rush out and break down the door to my local Best Buy to get my hands on them, but those are two examples of titles I would add to my own library. Two out of a couple of dozen at launch.
On the whole, though, the vast majority of the stuff that I'm interested in for my own home video collection is probably not going to show up in this format for years, if ever. I'm talking about stuff like Battles Without Honor or Humanity, which just showed up in a combination Blu-ray Disc and DVD edition, or Tragedy of Belladonna, which was just remastered in 4K although I'm not sure that a 4K home video edition would be in the offing anytime soon.
I never worry about being able to buy the classics in any format. The big obvious titles like Taxi Driver or Star Wars are guaranteed to come to pretty much every generation of home video. But the stuff that I really care about is not guaranteed to show up, and so my enthusiasm for new formats like 4K is muted. I don't worry about top-100 classics and blockbusters, because they have no end of representation, so to speak. And while there are people to speak for lesser titles — Criterion, Kino, Twilight Time, etc. — there's no sign they're interested in 4K, and thus not much reason for me to be either. My breath remains held.