The internet was good between the years of 2000 and 2010. From then it started to go down hill for enthusiasts and nerds.... but went massively uphill for the general population (social media, faceballs, instagram, twitface). It's not really these companies fault, they just saw a market that was obviously there and ran with it and it obviously paid off.
Facebook groups for things are just a disaster for everything other than getting likes on photos.
Facebook is losing numbers though, the teenages arent on it anymore. Do 17yr olds tinker with their first cars in the garage these days? i suppose so? where do they get their info?