Which one is the future? Or shall they continue to coexist? Can there be a scenario where both features are recommended to be used in tandem or interchangeably?
Hope you have gone through these differences before posting the question.
CRM Content needs separate licenses (Salesforce CRM Content User) where as using files do not need separate licenses.
CRM Content gives much more security and flexibility which Files doesn't provide that. Those uploaded files can be used for CRM content.
Mainly, it contributes how you deliver the content, you can put expiration date, password protection, downloadable URL for external users which cannot be possible without CRM Content.
Chatter Free users can use Chatter files which has been uploaded in chatter. External customers can see the files (if they join in private chatter group) and if the files have shared publicly.
Also, refer Salesforce CRM Content Implementation Guide to know more details.