This is one of the questions whose answer is not immediately obvious if you think only one step. If you generalize this in a society, riches will accumulate further over subsequent generations because it is easier to make money if you have money. Even if you are. It that skilled, your financial advisors will just turn your money into more money.

As a result, the split between poor and rich will widen and widen. Until at some point, where the situation will implode or be unfavorable in some significant way. Hence, to have a stable system, the limitless accumulation of wealth should be reduced.

There should be inheritance, of course, and half of few million is still lot. However, this requires some progressively adapting tax percentages, based on the amount of inherited wealth.