That is a very good question. At this point, I really don't know if there is a benefit besides keeping all the Freewrites in one place and when people are on Steem through the community, all they see are the posts of the other community members. So, the focus is on the particular community subject. That makes it easier to find all the freewrites without having to hunt for them all over the place.
Other than that, the only other benefit I can see is that it is a declaration of support maybe.
From what I had heard in the past, Steemit is supposedly developing other functions around the community. Like creating your own tokens, having conversations within the community and such. So far, that is not happening. But who knows.
for now, we are doing it because it is there and then, we see what will happen.

oh, and the cons - at least for me - is that you can only use 8 tags total and, the biggest of them, that you can't schedule posts in advance.