Oh, lots and lots.
> If people are that concerned, why do so many people I know have Prime?
The reason so many of the people you know have Prime is because of Amazon's dominant market position.
Yes. But if they are THAT concerned they would be dropping Prime and shopping elsewhere.
The "lots and lots" - if they exist (you added no link) - are likely to be the Coastal Elites. The same minds who were so out of touch we got DJT. Regardless, to think that Middle America is going to go from "build a wall" to "break up Facebook" is, at best, a stretch. As politics goes, this is a non-issue.
p.a. After the crash of 2008 we were told by many a political "leader" (including the POTUS at the time) how there was too much power concentrated on Wall Street. Liz W was one of those "leaders". Yet there were no breakups, etc. While I wouldn't put SV in the same class as WS, it's hard to imagine anything changing.