Who has a monopoly? There are still several major motion picture studios (Disney, Warner Brothers, Universal, Paramount, Sony, MGM, am I missing any?)...
You wanna split hairs?! Fine.
Hollywood's been an oligopoly for decades now, almost as long as the film industry exists. But in the last decade, Disney has made strategic moves to become the monopsonic force of the market. And looking at the movie business, they've pretty much succeeded. Thanks to Marvel, Star Wars, Pixar, the live-action remakes of Disney classics, and now FOX, they have nearly eliminated the competition in big budget movies. WB and Universal might still be their biggest competitors, in theatrical releases at least (and more on that later), but they still don't even come close to Disney's market share. Paramount and Sony are clinging on, but even MGM is pretty much dependent on co-productions and lower budget movies.
What's more, Disney has made aggressive moves to hurt the other movie companies. They've staked out the most lucrative release dates for years, and continue to do so. WB has announced a Batman versus Superman movie?! Let's put the third Captain America movie against it and use most of our Marvel heroes in it to make it as much of an event movie as possible. See, WB budged and moved to another date. FOX won't let go of their Marvel licences? Let's downplay the comic books they have the movie rights for, cancel them if need be. What's that, WB just had a massive success with Aquaman? Let's take a break in Star Wars movie and then release the first one in years in direct competition to their sequel.
Now, to be clear, this is all about the business side. The creative people actually working on the movies are quite friendly to one another, actually congratulating each other when they have success. And business-wise, all the movie studios are evil corporations. But Disney, with their buying spree and aggressive moves against the competition, seems to have a strategy of hurting the competition enough for those to be forced to put parts of their companies, if not their entire companies, up for sale, and then buying those. Disney appears to have the goal of becoming a monopoly, and the trend is certainly going that way.
... and more streaming services than you can shake a stick at. If anything, streaming services are the OPPOSITE of a monopoly. There are starting to be too many and could use a culling.
The question is, who owns those streaming services? If two of the top five streaming services (and Disney+ certainly looks to be going to be in the top three) are owned by the same company, which coincidentally is the same company having a monopsony on big budget theatrical movies, the same company owning the biggest comic book publisher, as well as owning the most lucrative licences (plural) for merchandising), then yeah, that is worrying.
Also, Netflix briefly got bigger than Disney as a media production company, and it appears to have made Disney determined to harm Netflix.
Looking at the big budget productions they've already announced, coupled with a very low subscription rate, it looks like Disney+ will be using the same strategy as Amazon (and Walmart before that) did in regards to retail competition, using their own financial security to do unlucrative pricing in order to drive the competition out of business.
While Disney might not want to drive Netflix and other streaming services out of business, they certainly appear to want to take a similarly monopsonic position in streaming as they already do in the movie business. I also expect Disney to continue its buying spree in the streaming world, buying up other services.