in their ranking algorithm. I have seen sites in the health category where big sites, funded by professional money, to the tune of 10s of millions, get to the first page for all the main health terms overnight. Just because they are massive does not necessarily mean they always have the best content on every topic. But when you are a massive brand you automatically get a massive social following, which in turn keeps you at the top of Google. This is in turn likely helps Google get the top dollar for their ads.
Another scenario. It helps guy A to rank higher than guy B because A is much more skilled at social marketing than B is, even though B has the better information on his site since his content helps the end user a lot more.
I also find a lot of stuff on social platforms like FB to be junk. FB reminds me of MySpace from a few years back.