> DRM made a promise to business that it would control content in ways that would let them extract more money from users and make it much harder for them to copy or use the content outside of approved uses.

1. If you think it's harder for users to copy or use content outside of approved usage, choose your favorite TV show, and type the name of the show with the text "s01e01" into Google. You'll find links to stream it in low quality or torrent a high quality MP4.

2. Meanwhile, try downloading a book from Amazon and transforming it into epub so you can read it on a different reader. If you manage to figure out how to do that, please let me know.

It's not at all clear that the minor difficulty of 1 prevents so much lost profits that it outweighs the profits lost from 2. So it's absolutely not clear that DRM has resulted in extracting more money from users.