Control publishing rights, platforms, software and hardware that is used for the consumption of said media.
The publishers control the DRM, which then needs to be licensed by television makers, software writers, and such things. Then that gives them control over how is it presented, how it is sold, how it is consumed and it forces everybody to agree to their terms.
It is a power thing. They want to have power over other businesses. DRM laws help them do that.
> How are these DRM schemes actually being defeated?
Well I don't follow DRM piracy stuff, but at a high level the people that want to consume the media must be able to decrypt it to enjoy it. So if you buy one of these DRM devices and figure out how they work then you can decrypt anything that is compatible with them.
And you only need to decrypt it once since digital media can be copied a infinite amount of times.