Wikibooks and Wikiversity are pretty different. The former is about book-like or tutorial-like content (not just textbooks, but mostly any non-fictional content) that doesn't fit in the reference-work format of Wikipedia, whereas the latter is a catchall project for useful education-focused content. Wikisource hosts complete primary sources where allowed by copyright, while Wikiquote focuses on short well-known citations, including from modern works.

But yes I'm pretty sure that Wikispecies would not exist if it was proposed today, Wikidata has basically superseded it. The Wiktionary is a lot more popular but it could also end up being broadly superseded by Wikidata's lexical content.