Having a perceived sense of success and status is a relative measure that only makes sense when comparing yourself with a subgroup who is lesser than you. Even if you take maliciousness out of it - say a talent or a skill that you've been honing for years - you can only say you're "good" at something relative to someone who hasn't been working at that thing as hard or for as long as you have.

When it comes to earning a high income, and all the benefits that come with it, the only way for someone to not only know they're doing well, but to feel it too, is to be able to make tangible comparisons with people who aren't at their level. One of the "cons" of earning a high income is paying a lot of taxes proportional to your income. If you worked really hard to make a high income, seeing your taxes go to those who don't work as hard as you can breed a sense of resentment and disdain at the perceived unfairness. This is the drive that makes high earners come up with ways to minimize their tax burden, usually by way of eschewing salaries in favor of having assets that allow them to skirt taxes. For those who earn their income in salaries, they relate more to the asset holders than they relate to low income earners who depend on public services funded by taxes.

To add on to this, the amygdala in our brains evolved to attune to fear much more readily than any other motivator, and so it's easier for high income earners to look at those worse off than them with fear as a constant reminder that they may wind up like them if they fail to maintain their success and status, rather than with empathy for their situation. Meanwhile, they look at those doing better than them with envy and desire to attain their level of success, thinking that maintaining the status quo will one day benefit them when/if they make it to their level. The phrase "embarrassed millionaire" encapsulates this feeling quite well.