tangental but there's something in this particular type of ravishment fantasy (and bdsm fantasy in general) where the situation and/or multiple characters are weight-bearing in the removal of agency, so that one or more "ravishers"/"protectors" are exempt from fault for the whole of the victim's/sub's/ravishee's disempowerment.
in project hail mary, we have a three-way structure for grace's situation: there's stratt, who does the heavy work of stripping grace's agency; rocky, who happens across grace and picks up certain power dynamics left lying around so to speak; and the situation itself, wherein grace is marooned in deep space, busting his ass to save his planet and people, and needing rocky's help.
this can be a major dynamic adjustment to the nature of the fantasy, because it changes the morality displayed by, and available to, the power-wielding character.
rocky didn't engineer the potential ruin of two worlds to get grace into his power. rocky didn't kidnap grace from his homeworld. rocky just steps into the shape of power made available to him. if he had gone to earth and kidnapped grace, if he had been stratt as well as himself, the dynamic between him and grace would have been vastly different, in ways that would make the fantasy better for some people and worse for others.
(by the same token, stratt isn't rocky; she engineered his kidnapping and the stripping of his life from him, and was not awaiting him in deep space with a gilded cage)
(and the star-dimming plague itself is, of course, nonsentient and neither has functional blame nor takes part in the "reward" of owning and keeping grace)
this dispersal of responsibility allows for the captor-character to be worth more trust from the captive; to be good, which has value to some people's fantasies in this regard.
it's the same abstraction of fault that we see at play in many hierarchical scenarios commonly used as the setting for both bdsm and romance stories: a story where one person holds power over another because they're nobility, or an employer, or a commanding officer, or an enemy, or a teacher, or a government official, or a master of apprentices, servants, peasants, or slaves, or whatever else they might be, all puts a significant amount of responsibility for the subordination of the other person on culture and/or situation, which means the other person is not the sole source of the antagonism.
(this is, I highly suspect, a great part of why fifty shades of grey bothered so many of us: that there was no inherent hierarchy at play, just a man using his own personal power against a woman he dragged into the situation personally; if he were a duke or a space marine or a vampire (yes, I know) in a society that overtly allowed dukes or space marines or vampires to rule over hapless subordinates he wouldn't have shouldered the whole of the responsibility for being, well, him. and that makes him hotter to some people, and skin-crawlingly creepy to others.)
also, as someone whose preferred shapes of bdsm tend to feature quite a lot of this outsourcing of avenues of oppression to the setting and scenario, allowing for a great deal of trustworthiness/goodness/safety in the dominant partner, I find that this discussion has done a great deal of heavy lifting in terms of helping to articulate why I like some things and loathe others.