The need is to prevent a situation as described in the post -- one where the party in a lower power position can charge that the party in a higher power position abused that power to force them into a relationship they did not consent to.
The more disclosure, the less likely that it would escalate. At the very least, there would be records that either party could use if something improper happened. For instance, there would now be written records if later on the person with more power did attempt to influence promotions that they should have explicitly not been allowed to be involved in that process.
I don't know why the UK would be different from the US from a legal standpoint, except perhaps just generally that the US is a more litigious society lately.
The more disclosure, the less likely that it would escalate. At the very least, there would be records that either party could use if something improper happened. For instance, there would now be written records if later on the person with more power did attempt to influence promotions that they should have explicitly not been allowed to be involved in that process.
I don't know why the UK would be different from the US from a legal standpoint, except perhaps just generally that the US is a more litigious society lately.