Companies that sell these DRM schemes, or the groups of companies that come up with the “standards” and ask for a licensing fee, don’t actually believe the solution works to prevent piracy - the investors also do not believe this. They’re just happy to get a tiny fee whenever somebody in the world buys a CD, DVD, streams on Netflix, buys a monitor, a cable, a console, etc.
It’s like creating a closed source media codec, but even easier because you can justify it’s cost with fear.