GP answered why the UNESCO lists help, in their first sentence:
> The biggest benefit is in bringing legitimacy to preservation efforts and curation of historic records (photos, videos, data, binaries, sources) on the history of the Demoscene.
It's not necessarily about "effort" but perhaps more about "appearances" - it's easier to say "This history is important enough to be recognized by UNESCO: give us money to preserve it!"
> The biggest benefit is in bringing legitimacy to preservation efforts and curation of historic records (photos, videos, data, binaries, sources) on the history of the Demoscene.
It's not necessarily about "effort" but perhaps more about "appearances" - it's easier to say "This history is important enough to be recognized by UNESCO: give us money to preserve it!"