Lawyers, platform moderation, and SEO have wiped it out. What’s left is boring drivel whose only purpose is to sell you a product or a course or avoid a lawsuit. I realize some have moved to private groups and there are still sites if you look hard enough. But is that enough?
Federation feels like the right place to bring that culture back rather than let it die or has that ship sailed?
Check out the kiwix library, it’s not social media but you can download all sorts of wiki-style sites as .zim files. Wikipedia, Project Gutenberg, DevDocs just to name a few. If you have an app that can read .zim files, it’ll open them just like a wiki site.
It’s probably a lot easier than scraping social media. But if you really want to do that, there’s probably a python package for it.
If you have specific DIY projects, you’ll probably find instructions on ifixit, instructables, or wikihow. Or find some really niche hobby websites and browse their forums and tutorials.