There is an underlying "tragedy of the anticommons"[1] problem that will be exasperated even if kids and young adults stop consuming mass media.
For example, Wikimedia Commons and Wikipedia communities almost refuse to believe any performer, label, TV/film/game studio, etc would ever release their work under a CC-BY license, even though some of these parties (as large as Warner Bros and Amazon) have a pattern of doing so in the past, probably for marketing purposes.
Typical attempts to justify why an entity is unable to distribute copyrighted content as CC-BY include:
1. Someone pressed the wrong button and marked the audio/video as CC-BY.
2. A separate marketing company may be responsible for social media accounts or website and they didn't have permission of their client to upload certain audio/video, or didn't have permission to distribute with a CC-BY license.
3. The copyright is owned by a production company which is a subsidiary of a parent company. The distribution and marketing of the copyrighted content is handled by a separate subsidiary company of the parent company. Both companies may even be led by the same vice president / CEO of the parent company. However, the theory goes that one subsidiary may not have the permission of the other subsidiary to use a CC-BY license. The CEO of the parent company also may not have the permission of the subsidiary companies.
4. A performer or label may not have gained the permission of ALL rights holders of a work to release under a CC-BY license. What if the movie studio did not get the permission of one of the multiple script writers, the person holding recording rights of a background song, the writer of the lyrics to the background song, etc. In an extreme case, perhaps a random person comes along later to claim that the movie contains a background song, the background song contains a sample, and the sample they consider to be a copyright infringement from another work.
The problem is that if you're an indie filmmaker and release a trailer to your film or excerpts from your film with a CC-BY license, the tragedy of the anticommons situation means that people won't believe you meant to or were allowed to use a CC-BY license. Even releasing all the complex web of contracts between rightsholders in your film wouldn't stop people from disbelieving in your ability to distribute with a CC-BY license.
[1] https://en.wikipedia.org/wiki/Tragedy_of_the_anticommons