I assume you mean "relative to people that are less successful". The answer is because the marginal value of wealth decreases the more you have.
If you're poor, $1,000 is the difference between your kid seeing the doctor or not. If you're rich, it's a nice meal out.
> There are some systemic issues that cause wealth inequality. We should focus on fixing those issue to enable more people to enjoy success.
The core systemic issue is that wealth is a positive feedback loop. The more you have, the more you can leverage it without losing it in order to get more.
Treating all levels of wealth the same is directly incompatible with resolving this positive feedback loop. You need a counterbalance that scales with the level of wealth, because the magnitive of the positive feedback loop does.
Fix the problems that exacerbate wealth inequality.
Remove regulations that inhibit competition.
No business is too big to fail. (Most big banks would have been destroyed in 2008)
Stop manipulating the currency to the benefit of the investor class.
There are some systemic issues that cause wealth inequality. We should focus on fixing those issue to enable more people to enjoy success. Not trying to take from the most successful individuals in the grand game of life.