From what I can tell, this was first suggested in July 2009. And there is no shortage of duplicates since. I found at least eight (all marked and closed as duplicate, the latest one being in July 2013) with this one being the most useful, but it was also originally posted in 2009.
So without closing this as a duplicate of a very old post, I would like to revisit this issue from today's perspective.
If I know my SE history, there were no other sites in 2009. Only SO and MSO. I'm not sure if the staff had any idea at the time that there would be so many other sites with such a wide variety of topics. Looking at this exclusively from SO's perspective does a disservice to the other sites, which is what the old answers on the 2009 posts do. Consideration for the entire SE network was simply not possible then.
My major point is that answers on a good portion of other sites are either abundant or extensive, and sometimes both. On the English site, for example, I notice that answers are typically short, but there are quite a few. Sometimes dozens. As a user of the site, I might really like an answer that is basically in a sea of others just like it, but I have no control to put it at the top because it is not my question. On the Christianity site, as another example, I notice that answers are typically very long, and most of them are very good. As a user of the site, I might really like an answer that is also in a sea of text, but I have no control to put it at the top.
This even rings more true for the meta sites. When I point a new user to a meta post, I almost always point to an answer, not the question. Having all the great answers on meta in my favorites would be extremely valuable for quick reference.
SO, by comparison, typically has short answers and only about three average per question. It's not a big deal to scroll down because it is not that much to sift through. On some of the other sites, it is a significant hassle.
So let's revisit this feature request from today's perspective with consideration for the whole SE network. Is this a feature request that the community wants and the SE staff is willing to implement?