Codeberg was asking about this. The linked toot by a commenter points to :
These are CC-BY-SA 4.0 remixes of the Stack Exchange Creative Commons Data Dumps. 100% Unendorsed by Stack Exchange, Inc.
They are minimal. They provide the data you probably care about and the data you need to comply with the original license in SQLite format.
Especially with Lemmy getting support for plugins soon, I don’t see the need for making a new platform
A new sorting method for “unanswered” is a cool idea. I’m not sure if it’s quite as simple as just finding posts with 0 comments, because people can put additional questions in the comments but it’s still unanswered. Also how do you sort them for posts with the same number of comments/answers. But this is definitely something that a plugin could handle.