Wikidata, Wiktionary, and Wiki Commons all heavily contribute to and compliment Wikipedia.
Wikinews is fine. It's not original but it's also not harmful to have more in that space.
Wikibooks and Wikiversity seem like they should be merged. Same for Wikisource and Wikiquote.
Wikivoyage is just not well made and there are other better projects out there
Wikispecies should just be a result of Wikidata, not a new project. Catalogue of Life (taxonomy) is much more thorough, rigorous, complete, and maintainable. No academic would use Wikispecies over COL. Misguided hobbyists might and that's a problem. And Open Tree of Life (phylogeny) already (thoroughly) serves the purpose of centralizing phylogenetic studies so there's really no unique thing Wikispecies provides and it gets outcompeted on the things it does provide.
Wikifunctions... I'm gonna be honest. I really think it's not well thought out and wish it didn't exist. I know a lot of people have already poured in a lot of effort into it and I always hate to shit on that, but as a long time Wikipedian I hate to see Wikimedia's name backing this up. Especially when I feel there are already other efforts out there that are more complete, better thought out, and better organized that would benefit from more contributors
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But yes I'm pretty sure that Wikispecies would not exist if it was proposed today, Wikidata has basically superseded it. The Wiktionary is a lot more popular but it could also end up being broadly superseded by Wikidata's lexical content.
Wikinews is fine. It's not original but it's also not harmful to have more in that space.
Wikibooks and Wikiversity seem like they should be merged. Same for Wikisource and Wikiquote.
Wikivoyage is just not well made and there are other better projects out there
Wikispecies should just be a result of Wikidata, not a new project. Catalogue of Life (taxonomy) is much more thorough, rigorous, complete, and maintainable. No academic would use Wikispecies over COL. Misguided hobbyists might and that's a problem. And Open Tree of Life (phylogeny) already (thoroughly) serves the purpose of centralizing phylogenetic studies so there's really no unique thing Wikispecies provides and it gets outcompeted on the things it does provide.
Wikifunctions... I'm gonna be honest. I really think it's not well thought out and wish it didn't exist. I know a lot of people have already poured in a lot of effort into it and I always hate to shit on that, but as a long time Wikipedian I hate to see Wikimedia's name backing this up. Especially when I feel there are already other efforts out there that are more complete, better thought out, and better organized that would benefit from more contributors