Maybe not the only factor, but a strong contributor. It's at least a few things:

- Broader awareness, as you suggest. Police violence didn't necessarily increase, but the number of videos documenting it did, as did the distribution.

- Highlight-reel effect on social media, so it feels like your peers are richer and happier than you. With previous generations' mass media, it felt like there was a separate "rich and famous" class, but the perception of the average person was a lot like yourself.

- Tribalism from market segmentation and the echo effect. So we learn less tolerance and our convictions get stronger without reasonable, respected counter-arguments.

- Actual increase in inequality through automation and globalization, without sufficient mechanisms (e.g., higher taxes, UBI, etc) to re-distribute the gains.

Seems to me the constant harping about it (both by media and loud voices) is a self-reinforcing story. In the actual meaning of the word "meme".

The world has never been more full of choices and opportunities (as in "things that one might do" - as opposed to a more limited but fashionable "next job one step up"). And extremes in the world are still just as irrelevant to our own lives as they have ever been - whether you envy Jacques Cousteau or Jeff Bezos. In that what they have is not added or removed from your life (although what they achieved added to our lives - if you see the distinction), but you are still free to use them as models and steer your life by them.

What has changed:

- the harping

- the spectrum of actual possibilities in what we can be

- our self-awareness that we fall short of what we might have been

How could it not be?

If someone was doing much better than you it would be hard to know or it was more formalized within the social hierarchy itself: nobles, kings, etc.

Now all you have to do is open social media and see dozens of people doing things you could never even dream of doing.

Inequality has clearly increased across the entire world.