Income inequality is a misleading metric. I would argue that equality has vastly increased over the years.
The rich don't really live much better lives than the middle class.
Rich or poor we all have roofs over our heads, we all have access to relatively affordable methods of travel to get anywhere in the world in a day, we all use the same IPhones, watch the same movies and drink the same Cokes.
The things that the rich have access to aren't really that much better when you compare it to the old days when you contrast Kings living in Castles to the 90 percent who are just worrying about their next meal.
The world has never been more equal.
[1]: www.forbes.com/sites/maggiemcgrath/2015/01/07/majority-of-americans-are-one-surprise-away-from-financial-disaster-survey-says/
> It's also about job security, your chances of getting promoted, autonomy, fulfillment, and so on
For a large number of people in the world, they are wanting food, basic safety, and healthcare.
Being well traveled isn't usually seen as helpful training for ignoring beggars and minimum wage people who need food stamps to eat, but there you go.
I think you underestimate how bad things used to be.
Today, if something unexpected happens, you are almost certainly not going to die by like next week.
You absolutely can though. There are lots of premium soda brands out there on the market that cost significantly more than Coca-Cola that are made with better ingredients (such as real sugar, not HFCS), that are healthier for you, that use better artificial sugars, that have real flavoring so they don't need as much sugar to taste good (see GuS), etc. Or compare the homogenized product of "Simply Orange" (a Coca-Cola brand) to real non-additive orange juice that costs several times as much but is way more delicious. Or hell, look at how insanely expensive kombucha is ...
My point is that you are introducing a completely artificial rule by limiting things to Coca-Cola, when in fact there is an entire spectrum of drinks out there, and you can spend significantly more money to get a significantly better product. The very rich do not drink nearly as much Coca-Cola as the poor; they have the money to afford better options, and so they do.
Though I would argue that those options are only marginally better, and may as well be the same.
For example, most people can't tell the difference between a 20 dollar wine and a 200 dollar wine. So the rich and poor effectively have access to the same thing.
And by the way, the poor absolutely are not drinking $20 bottles of wine. Alcohol consumption is significantly higher in the rich than in the impoverished, because when you struggle with putting food on the table everyday and keeping a roof over your head, any kind of alcohol is a luxury. I don't think you really know how bad it is for lots of people. A large number of Americans don't even get the choice between $20 and $200 wine.
Humans happiness isn't concerned with absolute standard of living but more comparative standard of living. I don't mean just conscious comparison in a competitive manner, I mean in setting what counts as normal to our brains.
Consider the standard of living we've obtained compared to what humans had for the vast majority of our 200 000 years. Regular hot meals, basic medicine, and being able to fall asleep without fear of waking up to tigers ripping you and your family apart should have resulted in us all walking around in pure bliss 24/7 if advancement in standard of living was all that was important in absolute terms. But we're not. Some of us are happy. Some not. Some so unhappy that we straight up kill ourselves. Neither do I think past generations of humans, or any other animal that hasn't achieved our current standard of living yet, are all walking around in misery.
Instead we care about comparative measures. How am I doing compared to how I was doing before. How am I doing compared to my peers. How am I compared to the guy down the street. How am I doing compared to all of those people I see on the internet/tv. Again, although phrased as if it's a conscious mental decision here, it's about subconsciously setting a 'normal' that's greater than we have. Think of the whole facebook making people feel inferior thing because they only see their friends highlights reel making life seem like it should be one long maldives vacation, except with inequality it's not an illusion and you actually are being exposed to better lifestyles.
So inequality isn't fundamentally detrimental, however exposure to it is. At its most extreme it shows you fantastical lifestyles you could never realistically imagine to live. More realistically it's your neighbour buying a nicer car than you have. Either way it takes the great thing you have going and puts it in to a context within which it can't compete.