My previous employer, Booking Holdings, then the Priceline Group and one of the largest e-commerce companies, treated these kinds of issues with a lot of respect. So much so that allegations were investigated by OUTSIDE counsel, who then also made the call on how far to go in the investigation. This led to the dismissal of the group CEO (relationship with indirect report) and number of other execs over the years.

There was also always a way to (anonymously if need be) report such things to a third party (not just hr). Managers and execs generally considered it a feature, not a threat. Every so often, somebody would try to use the mechanism for a vendetta, but best I can tell (and I've been involved in a few of these investigations), those were effectively recognized as such and treated with respect for accuser and subject of the complaint.

In other words, this is solvable problem.