To be fair, I'd wager the overlap between people that are on Lemmy, know what F-droid is, but wouldn't think to just Google it is pretty low. Those people probably shouldn't be messing around with sideloading and alternative app-stores anyways.
I dislike the "Why not just Google it?" argument because I've arrived at too many forum/reddit/stackoverflow posts that are the top Google result with comments on them saying: "This information is already on Google"
I would love it if Lemmy could start to curate information so that instances start showing up in search results more.
I agree up to a point. In an instance like this, what is there to document? The steps to install F-droid are to go to the website and get it.
For things where there's actual discussion to be had, or answers that require some degree of critical thinking that can have value in the future, sure.