A few months back a bunch of big Facebook advertisers (nike, etc..) pulled back some of their ad spend to punish Facebook over their stance on certain cultural issues. What happened to Facebook? Nothing... Revenues actually went up...
Facebook is an incredible tool and platform. No platform (none amongst the FANGs) has the same capabilities of tailoring your internet experience like Facebook does. As an advertiser, this is incredibly powerful: being able to put a targeted tailored ad in front of exactly the demographic you want. No other platform even comes close.
The cultural impact will be zero. The dollars speak for themselves. FB users keep using the platform and advertisers will keep chasing them on it.
The only way to put this in check is for government to step in and put in a comprehensive set of laws and rules that governs how your data is shared. A market-driven response to Facebook's insidiousness will not happen by itself. Government needs to nudge it forward with a thoughtful set of policies that promotes competition and makes these big companies liable for the false information they promote.