I'll still argue that HD-DVD is mostly the better technology. The things which BRD tried to claim were what made it better were not things which would fundamentally have stayed with BRD. The interactive layer was finalized first on HD-DVD and was better.
All that said. I have many HD-DVDs and the drive. Before my drive fails, how would I archive my movies. 🤔
When does something become an OS feature and when is it an add-on? Consider the use case. If you need to make a backup or restore data from one, by having this as part of the OS it is always available. It's line having vi installed; it comes with every Linux distro, but a lot of folks use Emacs. It makes sense that this should be a system component.