For physical releases you buy the disk and the right to watch it under certain conditions (DRM).
I’d like to point out German law (maybe this expands to EU and other countries) with traditional media.
Traditionally you bought movies and music on physical discs. You had a guaranteed right to be able to sell it to other people, as well as make personal copies of it for private use/backups.
DRM has always tried to oppose this right. And obviously, in the last decade(s) a lot went into service-oriented streaming and temporary access instead of owning even on a partial or theoretical level.