It is partly due to new media however lets consider some other things which are really important.
1) The problem is that a lot of the remakes/sequels and reboots are quite frankly crap. I don't care too much about Disney. But other remakes and sequels are generally awful.
So lets take some case studies:
* Robocop (2013). The movie except for on 2 minute scene was dire. It was a PG-13 remake of what was at the time a shockingly violent film (the effects look awful now, but they were quite convincing back in the mid-90s still) that completely missed the point of the original movie.
* Ghostbusters (2016) was another movie that not only looked completely awful in the trailer, it completely again misunderstood the original movie, added nothing much new and they outright attacked the fandom after they said to the studio "What the hell are you doing". The original Ghostbusters movie wasn't really a comedy movie, it was a Action Horror with some Jokes. The new movie was just a comedy movie, which looked like a Spoof along the lines of "Scary Movie". I have no idea who they were marketing it towards.
Lets take sequels:
* They have also totally squandered two solid Sci-fi Action Movie franchises (Alien and Predator) to the point where the previous low points of the franchises look good (Alien vs Predator and Alien 3 & Alien 4: Resurrection).
* Star Wars has been completely ruined from a fan's perspective. The prequels (in the 2000s) has some terrible acting, iffy CGI now but I can at least appreciate what they were attempting to do and it was an honest attempt by Lucas to flesh out Star Wars universe. However the new Sequels go from "This is Okay, but it is the 1977 movie retold essentially" to terrible (The Last Jedi).
The Last Jedi doesn't make any sense on quite a number of levels. It also ruins one of beloved characters on screen and it was probably intentionally written to not only upset the fans but also kill the franchise i.e. there is at least one scene where Kylo Ren says to audience pretty much "Let the past die, kill if you have to", which is the director pretty much sticking his middle finger up to the fans. Yes in the scene he was speaking to whoever the main character is that doesn't seem to have a personality, but it was really a message from the director to the fans.
They also attacked the fan base (not a good move) because they didn't like a terrible movie. While the movies made money, they have tarnished the brand in the long term.
Disney bought Lucas Film because of Star Wars and monetising the fan base. Lucas Film under Kathleen Kennedy have tried driving away their a dedicated fan base. This strategy is madness.
2) The Hollywood Elite (and they are Elite) have forgotten they are actors and actively show distain for the audience. I don't really want to get into a political commentary, but they literally had The Avengers do an online piece of activism where they told the Electoral college to defy the 2016 Presidential Election result. This doesn't go unnoticed by the average movie goer. Just under half of the Country voted for the current president and then they do an advert where they are pretty much putting a middle finger up at the people who voted for Trump. A lot of those people took their kids to see those movies or saw went to see them themselves.
Audiences will forgive actors for quite a lot of things, but if they continually keep on pushing this audiences will associate them with their politics and not what roles they played.
They are actors. I want them to pretend to be Black Widow, not lecture me about Politics. I will go and listen to a political commentator if I wanted that.
3) Bollywood and the rest of Asia are making their own movies which kick ass. Take "The Raid 2". It has plenty of brutal fight scenes, but it also has a top quality plot about gangs, undercover cops etc. It is amazing to watch. A lot of guys are looking at overseas cinema because Hollywood isn't catering to them.
4) User generated content. I think the only movie I've watched recently was John Wick 1, 2 and 3. I recently listened to a recorded lecture series of the History of Islam on Youtube made by some guy who lives in Azerbaijan. I can listen for effectively nothing 1000s of hours of interviews of Joe Rogan and a Guest just talking for 3 hours about sometimes absolute nonsense or talking about say Leaving a Cult (Megan Phelps interview). I recently watched a series of lectures about the database as a filesystem from some Linux conference. There is a guy who made loads of mini-documentaries about old defunct computers systems and the quality now is on par with the Discovery Channel shows of the late 1990s.
5) Longer stories. Game of Thrones, The Wire and other shows that have very long running stories, lots of characters and complicated plots with lots of Lore have proven that audiences want more complicated stories. There is a guy called Alt-Shift-X on Youtube and he has huge number of people watching him and he just explains the Game of Thrones Lore of the Book vs the TV-series. Most Hollywood movies are pretty simple affairs in comparison.