You've misunderstood. Ubuntu's TPM-backed full-disk encryption isn't DRM like the type used to prevent you from copying movies. It's meant to assist your own

You've misunderstood. Ubuntu's TPM-backed full-disk encryption isn't DRM like the type used to prevent you from copying movies. It's meant to assist your own privacy and security, by prevent other people from accessing your own data. For example if your laptop is lost, stolen, left in a shop, seized by bailiffs, sent in for a repair, etc., or if it's a server in a data center, making it more difficult for someone to read the server's data without authorization.