It's more big picture. Your individual data is useless. The data of a huge % of the US (or other country, or planet) is extremely powerful. As a facebook user you contribute to that data.
So, no you individually using fb or not doesn't really matter other than on principle. I don't use it because I find them morally reprehensible, but I also understand my boycott is purely symbolic unless another 100m or so people join me (probably won't happen).
More likely a boycott will prove unnecessary; the biggest threats to Facebook are (a) fashion and (b) facebook.
... but not using Facebook makes me feel better.
I think Facebook will slowly decay into irrelevance.
One thing that really surprises me is how few startups are taking on Facebook. Obvious strategy is to work at the edges; there are so many opportunities abound to undermine them. Don’t build a new Facebook, instead just carve off their features incrementally and be the Instagram of events, classifieds, chat, video, news sharing, interest groups... huge scope for innovation. Facebook is the SAP of social networks, it’s time to move on.
So, no you individually using fb or not doesn't really matter other than on principle. I don't use it because I find them morally reprehensible, but I also understand my boycott is purely symbolic unless another 100m or so people join me (probably won't happen).