FaceBook won’t overtake forums for a bunch of reasons:
–Censorship of FB sways from whatever internal policy fits current US events, for example FB keeps tweaking their news feed by “delaying” certain types of news content or holding them in a que. Twitter recently rolled out a similar concept but instead of bringing community standards you saw them censoring/banning political news/commentators from the right at abnormal rates who never spewed the degree of hate as Trump yet someone who is a lefty can get away with hate speech. Take a look at whitelisted news on FB, many stories keep fueling Hillary is the default nominee of the Democrats like on TV yet she is facing the Bernie or Bust movement of >45yr crowd who won’t vote for her in the general election(Iraq war vote is a key factor, ties to Wall St & Tony Blair papers/emails over the Libya situation), if she does beat Trump via Never Trump boost it’ll be in the low digits(>8%). Keep in mind FB censored Tuesday’s news of Sanders win by delaying news feeds, if he wins California you might see a brokered convention on the scale of how Obama became the nominee. Hillary has used DMCA to remove any audio references to her creation of the “birther” movement from the 2008 primaries and I’m sure that is why Trump kept beating the dead horse knowing Hillary might run again. This election is going to turn ugly and censorship might creep into play on a wider level in social media.
–Terms of Usage is flawed to help marketers in using your likeness, they got the wraith of US state AGs in which if you liked a page/product the likeness(your photo) would display on friends’ pages in the form of ads. There isn’t any opt-out for this unless you live in the EU or change your location to an EU country.
–Legal rights are at risk upon liking a company/product. The ability to sue a company in the US of A is lost if the product injures or results in a food-born illness… why would you like a company/product if it could harm legal rights in the future eh?
–Privacy or data mining, they’ve created so many new changes each year in hopes you’ll forget to review those “tweaked” settings. On websites/forums the owners are more willing to keep a reasonable privacy policy and or carefully choose their 3rd party ad sponsorship. Smaller community forums typically only use ads to pay for hosting/hardware, I’ve seen owners who ask for input if/when revenue becomes an issue and ad decisions are a common discussion. In the era of toxic served ads, I don’t trust mainstream sites as redirects are a hazard/headache and plenty of forums are creating alt-news networks to counter the trend of ad block paywalls/blocking.