This is indeed a problem of capitalism.
But, it is better than the problem of socialism where everyone becomes equally poor.

When you have competition, those who are better make more money.
A good salesman can make 10x, 100x more money than a poor salesman.
And, we shouldn't stop this, else we wouldn't get all the good from the really good workers.

Now, talking about the taxes...
There can never be a fair taxing system, because the taxing system is designed to tax the little people into the dirt.

The FED and the IRS are one entity.
The IRS is needed to steal actual productivity from people each year or their ponzi scheme will implode.

The "rich" can never be taxed. They are completely outside of the system. They don't hold their wealth in Federal Reserve Notes.