Relationships within a reporting chain are a classic example of bad business ethics, because there's obvious opportunity for favoritism and bias, and most corporate policies disallow it (in favor of moving folk to other teams or similar).
More important IMHO in power differentials like this are the other side of that: punishment or worse.
Whether it's a real explicit threat or not, it's built in.
women especially have had these experiences for decades. I'm sure almost any women on HN has a story about some superior being inappropriate and the pressures around that.
Exactly. I don't care that Bill Clinton cheated on his wife, they may have an arrangement for all I know. I care that he used his position as the most powerful man on the planet to sleep with a young intern. As a counterpoint JFK and Marilyn Monroe doesn't bother me at all, the power balance was much closer in that case and she was more than capable of navigating those waters.
Or else what though? Get fired? I mean for instance, it's not like a man can just offer to have sex with their male supervisor to keep their job if they're straight. So the dynamic is also partly brought upon by the woman herself. It's very unfortunate but lets not act like she had 0 autonomy and no consensual actions involved here.
There's also a power dynamic at play which can make person to submit to their superior's advances to avoid any negative outcome. It's quite hard to consider such a relationship consensual.