HD-DVD was cheaper and required less immediate infrastructure changes, but rather allowed a staged switch from DVD.
Blu-Ray is the one that was better.
Actually this is exact reverse of a Betamax story - better and more expensive long term improvement won over short term and cheaper one.
And at it's core, BetMax is better than VHS. HD-DVD is better than Blu-Ray.
Often, it's not about what is "better". It's about who has the most moment, is easier, less encumbered by DRM, etc.
Sometimes it's better to download Youtube... more often than not, Youtube "just works".