I think the facebook sites might take more people who are in for a quick fix and never come back, but overall a good enthusiast site like TRS will always win out just for the fact that Jim mentioned about google not putting any hits for answers off of facebook. I think you will see the younger generation who wants everything placed in their outstretched hands (yes I do realize that there are some of the younger generation that are not like that
) gravitate toward facebook/ instagram, but for those that want to really understand the problem and fix it, and for those who are looking at keeping their vehicles for a long time, they will come to the enthusiast sites.
Social Media in general can be a tool for enthusiast sites as well, because it is an easy way to talk and interact in real time. you can back that up with posts pointing toward the enthusiast site, and get them involved in the site through Social Media.
Some enthusiast sites are crap holes, or devolved into crap holes, but I would say that I have not found a site better than TRS. Lxforums and LHforums are the closest to it. they both have the cameraderie that TRS has, but the tech and the know how (while darn good) is not up to the level of TRS.
AJ