Since your question is partly about tag-wikis, let me add a brief comment on this.
The main purpose of the tag-info is to give guidance on how the tag should be used. In many cases people who are familiar with the area know the intended usage just from the tag name. So this is more important if the tag-name is ambiguous1 or might be misunderstood by a non-expert.2 See also: What is a tag wiki? How do I write a good one?
The tag-wiki might be a good place to give some pointers to good resources about the topic and a very brief overview what the topic is about. (However, it is probably not suitable for a full blown introduction for some topic - similar to a Wikipedia or nCatLab article.)
It is great if some people do this - editing and improving tag-infos should certainly be encouraged. However, it seems that not many users of this site find the time to do this.3
Regarding a comment asking somebody to edit tag-info for a specific tag - I have certainly posted several such comments, you can find some of them archived in chat. However, it was slightly different situation - my comment was typically addressed to the user who created the tag. And the intention was mainly to have some guidance for the usage of the new tag on the site.
1A good example is that there are several tags for lattices - this word is used in several different meanings in mathematics. There were at least three posts on meta about this - in 2014, in 2015 and in 2016. The situation about tagging questions about these topics doesn't seem to be satisfactorily resolved.
2A good example is the tag (divisors). As you can see from the tag-info the tag is intended for divisors in algebraic geometry. But it is not surprising that some users just look at the name and use the tag incorrectly - you can see list of the posts where this tag was removed. (There is a proposal to rename the tag to make this distinction clearer.) Another example of a tag which is relatively often used incorrectly if formal-proof. (To make the situation worse, in this case the tag-info is empty. Again, I will add questions where the tag was removed.)
3You can check some stats about editing tag-wikis and tag-excerpts in these queries: Recent tag-info edits,
Number of tag-info edits (including deleted users) and Number of tag-wikis edited (only body).