I think the notion of "reach" is linked to our notion of "gap". We see a content "gap" and then we think maybe there is a contributor "gap" underlying it. But maybe there is also a source "gap" which underlies it and so on.
I think the same is true about "reach". While reach is inherently about readers (people), I imagine that (apart from inability to access the web for whatever reason), any shortfall in our reach must relate to people's lack of interest in our content. Given that search engines tend to drive people toward Wikipedia, I don't think lack of awareness of Wikipedia is the major issue here. Lack of interest in our content might relate to a content gap, e.g. we don't have articles about topics they are interested in, or not have it in their language, or because they judge the content to be inferior (or have been pre-conditioned to think it will be inferior, either by personal past experience or teacher/librarian instruction to "not use Wikipedia").
I think we can increase our reach by ensuring that the content we present is as broad and as deep and as authoritative as we can. And obviously more the citations we can provide to authoritative sources and/or online sources the better.
Aside, we do need to convince the librarians about Wikipedia being not as unsafe as they fear. But teachers are a different issue. As a former university professor, the concern about Wikipedia is not necessarily about the quality of the content but that the purpose of the assigned task is to develop the student's own skills in researching and writing (which is not achieved if they just copy from Wikipedia or any other source). As someone who does outreach with university librarians, it is clear that these librarians' position on Wikipedia is now shifting to a more reasonable position of "it's a good place to start but you need to dig deeper using its citations and other sources". Many of them explicitly discuss Wikipedia now as part of workshops they run for students on "how to research an assignment" etc.