IMO, the point of the romance can't be to succeed in a game without a pre-generated PC character1. Romances should be able to fail, and should be able to fail for things outside of the player's choice. Otherwise it is a pointless narrative device that violates the idea of allowing the player choice and consequences to those choices. We've talked about the idea that romances can be important in a narrative sense before, but having a romance that doesn't end well can surely be just as narratively interesting?
Additionally you should not have to romance a NPC to have an "immersive party" or "follower interaction" as that is forcing the player to meta-game (romance whether their PC would or not) in order to get an interesting NPC follower and is IMO poor design (and part of the reason, I think, people haven't always appreciated romances in games as it typically has meant exchange an interesting general character for one that is only interesting if you romance them).
1I think once you have a pre-generated PC character, you can make the argument that you are RPGing a specific character about which certain aspects of their story can be comfortably designed around the character and not around player choice, like in a lot of JRPGs.