So yes, inequality is technically decreasing between the poor and middle class, but the end result will be the middle class being non-existent.
It might be better for someone from a poor country, but not that good for someone from the US.
Besides, globalisation will overall increase the total wealth of the poor + middleclass combined.
It won't really increase the overall wealth of the middle class. It will pull wealth away from the middle class to pay the poor at a cheaper rate. This is what's happening right now and why people in the tech industry are so upset by it. It's a form of global wealth redistribution.
I also don't think the middle class has any divine right. They just need to start preparing for job loss and overseas competition.
...What??? If google was as good as some people claim, we should be able to look up something like U.S. automobile imports from 1950 through 2015. Also, NAFTA became law in 1994, and I'd argue that this is a lagging indicator more than a leading one. The culture at large (or at least the politically influential part) had to accept this first, before it became law.
If not in those countries, big companies like Facebook will just bring them over on an H1B visa at a similarly competitive wage.
It's the same phenomenon that happened when technology uprooted the music industry 15 years ago: small, indy labels can now no longer survive because nobody actually buys music anymore and we are left with huge labels.
Adblock will eventually do the same with independent blogs: If you want to make any sort of living, you will need to post your content on a large-corporate owned blog that has enough traffic to make money outside the ad system.