Why I Do the Discs
I like physical media for movies.
There's a lot of stuff on them there discs that you won't find on a streaming service.
Extra footage
Scenes filmed, but not included in the theatrical release of a film usually survive as a "special feature" available on physical media called "Deleted Scenes". Recently this is mostly a planned revenue strategy, but who cares. While generally not "canon" deleted scenes can change the perception of a film's narrative by expanding existing plot points and character development. At the very least the additional footage gives us a look at the history of the development from script to film and the connection between editing and storytelling.
Creator insights
Director and cast commentaries can sate the desire for a deep dive in a way you simply won't find on {insert streamer here}. For the the fully obsessed, learning how the film was made and what impacted the production is delightful. Commentaries are almost always good for a few laughs and occasionally introduce new information hidden in plain sight revealed by those in the know.
Alternate versions
Typically coming away from viewing a director's or alternate cut of a film leaves one with a sense of why they chose to go with the theatrical release in the first place. However, it is hard to beat the joy of seeing something like the director's cuts of movies like Aliens or Payback transform the entire story into something new. Unrated versions don't tend to change the story, but the tone of a movie can be impacted drastically by restoring scenes that were removed for compliance and marketing purposes. As crazy as it sounds, Human Centipede 2 uncut, is way more disturbing than rated.
Seeing the movie?
Not all movies are on streaming services. I looked today it did not take long to find a few movies that are not on streaming nor available anywhere digitally. Today, 2/17/2023, these movies are not easily available digitally. My tastes are my tastes and not being able to watch these would bother me. Feel free to look up some of your own favorites to compare.
If you are lucky you can find a non-streaming movie for rent for ~$3 or shell out ~$15/month for a subscription when it inevitably appears on yet-another-streaming service.
Buying physical media
Walk into any Goodwill and you'll find a mountain of films and TV on DVD & Blu-ray with all the extras, no rental fees, and no chance anyone can revoke your license to watch said content all for the perfectly reasonable and variable price of "a buck or two".
I fucking love Goodwill. Garage sales can be a bit more hit or miss, but also a solid choice. I stop into a local pawn shop now and then and recently picked up a 9-disc 4k Lord of the Rings collection for $10. That's 3 movies in both extended & theatrical cuts, all the special features, and in 4k resolution for $10, and they are mine forever, and in a very nice case with lots of niceties.
Most places today are bordering on giving physical movies away used, but if you want more limited and or fancy collector editions here is a list of sites you may find useful: