1. Descendants of really successful people tend to fritter away that wealth, thinking they're as gifted as their forebears. Look no further than the Vanderbilts;
2. Families have a tendency to die out over generations. The Roman Republican originally had 45 patrician families. By the time of Gaius Julius Caesar (who was from a patrician family), there were 15 IIRC; and
3. The ultimate form of wealth redistribution is war and revolution.
Most long-lasting family wealth tends to be monarchies of some kind.
Therea are a bunch of arguments you'll hear why taxing the rich more can't or shouldn't happen. They're all lies.
1. Capital flight. The rich will leave. Great. You lose the ability to sell to customers in our country then;
2. Taxing unrealized stock gains is impossible and/or unfair. We do this to property just fine. Companies produce tax statements of unrealized gains just fine;
3. The dreaded slippery slope arguments. "If they go after Bezos, next they'll come after me with my $42,000 a year job and 2011 Camry".
A stable society and political climate is completely necessary for this wealth to exist. Having the wealthy pay for the society that makes their wealth possible while avoiding their heads ending up on pikes or in guillotines is entirely just, possible and moral.