I'm a big fan of nepotism. If you've ever had to fill any vacant position within an organisation you'll know that the application process is long, arduous and can be a bit of a lottery. What takes a lot of the pot luck element out of the process is when someone you know and trust, who understands the function that needs to be covered vouches for an individual.
They know you and they will not want to lose your respect by promoting someone who will fail.
If it is a family member that can also be a good indicator. If the parent is a solid worker then the off-spring is likely to be too.
It might not be as fair as we would all like, but it is effective and efficient. Good business likes effective and efficient.
But there is a massive problem with nepotism. And we all understand it.
If the person makes the decision that the relationship is more important than the performance. You don't get a lot of nepotism amongst engineers, or surgeons, or teachers ... anything where there is a significant requirement for a particular set of skills.
And you don't need anything in the way of skills or qualifications to become a politician. You don't really need any relevant experience. Far better to know the right people who can put you in to a nice safe seat and assure you a place at the trough.
Part of the reason that this is possible is that politicians don't really make complex decisions. In effect they don't really contribute a great deal towards the progress of a society. They might tweak things around the edges but they will never make any significant change as it; 1. they don't really understand and 2. they will never expose themselves. Their ability is not all that important. It should be, but it's not.
We need to insist on better, more capable politicians and we must remove their ability to use malign nepotism to their own benefit.