You don't own media content. You own a license for media content. Your use of the media is dictated by its license.
In general you don't need a license to consume a copyrighted work that you received legally. There was no "click to agree" on the last book I read. You only need a licrense to exceed what copyright allows.
Some software companies have argued that the hierarchical storage of a computer violates copyright, and thus all software requires a license to run. But this case was not about software.
Note: not a lawyer, just a highly interested observer.
A number of courts have broadly agreed with those software companies. While you're correct that you don't need a license to read a book, this is true (broadly) because you don't need to make a copy of a book in any meaningful sense in order to read it.
But to run a piece of software, or read an ebook on a computer, or play a music file, you do need to copy it -- not just into hierarchical storage but also into RAM -- and this brings copyright into play (as far as the courts have generally been concerned), and thus necessitates all of the end-user licensing of digital media.
I guess that's technically what I asked for, but I don't think pointing out the existence of that statute does much for the argument that you need a separate license to run a computer program you paid for.
Let's try this again: Can you cite a relevant case that hasn't subsequently been invalidated?
Just to clarify, by "hierarchical storage" I mean the entire storage hierarchy of the computer, multiple tiers of which may contain a copy of any given data in use by the computer: registers->cache->RAM->HDD Cache->HDD[->backups]