Account identity and authentication being outsourced to Facebook means your community maintainers don't get to notice the fact that those 100 MAGA-spouting dimwits are from Romania. They don't get that information in the first place.
Let's revisit this in 2020. I have a strange feeling that React will still be heavily used (though maybe encroached by some future framework, you are correct about the changing landscape!) with Angular still trying to follow the leader.
I cannot wait to allow a bazillion fake Twitter and FB accounts from the Eastern Bloc countries to pour into my website and bigly MAGA. Thanks, social sign-on!
Opinion: the industry doesn't equate with reality. Pointy-haired MBAs with some PHP background would tell you otherwise, but there's a whole wide world out there.