I do some hiring in the US, so imma go ahead and do an [exposition]. Tis' firmly in the realm of opinion.
Nepotism in the US isn't a problem because someone hired someone they are already familiar with outside of the workplace. It's a problem when someone hires someone
because they are familiar with them outside of the workplace, or as a priority over their actual qualifications.
If I have candidate A candidate B, and they both have the *same qualifications, and I have worked with B in the past or have a solid pre-existing relationship with them that leads me to believe they would be trustworthy/competent in that role, I am going with B. That's not corruption, that's common fukkin' sense. Firsthand experience with a candidate
is a legitimate qualification. You can say that it's somehow unfair that B has an advantage, but the other way would be to deny B a job because I know them. That's ass too. In this case it's equally shitty to say that B only got a job because they knew someone, despite their qualifications.
Note: That's a common shitty reaction to women being hired for leadership roles. Clearly they only got hired because they know someone, somewhere.
Now where the corruption comes into it is when they are both NOT equal, which is obviously the overwhelming majority of cases, and someone takes candidate B over a more qualified A. As someone who has handled hiring and is NOT a shitty manager (Says me), I would prioritize any demonstrated or listed qualification over previous friendship. In fact the only time I've ever recommended someone I knew for a job was for entry level stuff where the sole qualification was "can press button on phone" and "can confirm firsthand that this guy shows up to work". Those positions are basically crapshoots for hiring where we have 1000 candidates on file. I don't think I'd be comfortable recommending someone into say, a leadership role. That where it can and does get shitty, because Chad from high school is gonna be super cool to hang out with in the break room, but it turns out his role as a shift lead at McDonalds did not qualify him to be CFO, and him and the 1000 people underneath him all get blamed for his incompetency and the incompetency of the guy that hired him. Usually its a "well if the lazy plebs (who have been here for 12 years and all said this was a stupid idea in the first place) underneath Chad worked harder to make up for Chad then it wouldn't be a problem now would it" sort of bullshit.
We do have nepotism laws for PUBLIC OFFICIALS AND STATE/FEDERAL DEPARTMENTS, but to my knowledge we do not for private business.