https://www.wikiwand.com/en/John_G._Trump
Not all of the family success was boosted by nepotism, there seems to be some talent in the bloodline, his sister was also a senior US circuit judge and was quite successful on her own.
Regardless I was talking about talent and achievements here not personality, and I don't think there's much use of discussing that here. It's been discussed to death elsewhere.
First, billionaires represent an extremely small minority of the human population. And second, notable people also represent a small minority of the human population.
So it seems reasonable that there are few notable children of billionaires, and this alone doesn't imply that billionaire offspring are less likely to be notable than the person. It only suggests that being the offspring of billionaires doesn't radically skew the probability of being notable.
If you like anime, Steins;Gate uses John Titor as a plot device (http://anidb.net/perl-bin/animedb.pl?show=anime&aid=7729)