Mario is one my favorite platforming series, but I felt that the Mario Maker games never quite reached the level of innovation of LittleBigPlanet. (Both in the tooling and the community.)
It looks like some users did the work to archive LittleBigPlanet, too:
People came up with all kinds of hacks to push the engine to its limits. They made FPS games, top down Zelda dungeons, and all kinds of crazy stuff with LBP. It was awesome.
I haven't checked out LBP's spiritual successor Dreams yet (I don't have time to game lately), but I've heard it's phenomenal.
That said, I do enjoy watching others try to clear some of the diabolically difficult levels that Mario Maker creators design.
I looked into Dreams a while ago. Dreams is more a general game engine than a level editor, including a highly unusual rendering engine that is not based on polygons. But apparently all this innovation hasn't translated in much success.
I know Nintendo will never allow it to exist in the open but is this a way to archive the actual levels or just a list of names/codes? I'm genuinely sad thinking about the (very real) possibility of them vanishing forever.
Most likely Nintendo (being an extensive AWS user) will just ship the levels to some S3 bucket; never to see the light of day. Even if each level were just 2 MB, that would cost them only $46/mo. to keep 1 million levels.
I think pretendo kinda does this? Someone who's more familiar should probably confirm/give caveats but I believe at the very least there are tools to pull down courses + metadata, but I don't known whether a public repository has been established.
This already exists online — won't link it here but it's easy to find if you know where to search. Players have been unable to upload since March 2021, so any archive that's a year or two old will still be up-to-date.