How do you think the Reylo relationship could’ve developed if there wasn’t the Force bond to move things along? Do you think there would’ve had to be some kind of “trapped together” situation no matter what for them to come to an understanding or develop feelings for each other?
Trapped/stranded together is the easiest and most common plot device to get two enemies to know each other and catch Feelings. That, or “must team up against a common enemy”. They’re often used in conjunction, and they’re not only fanfic tropes. Jaime/Brienne is a classic canon pairing that is developed using this sort of narrative device---they get a hellish Road Trip instead of literally Stranded Together, and they’re both captured by the Bloody Mummers (Roose Bolton’s minions) and then brought to Harrenhal when they bond over their mutual trauma and form a typical Fire Forged Friendship. Oh, and there’s also “the villain is captured / imprisoned and the hero goes to talk to him”, Silence of the Lambs style. Basically, anything that allows the hero to talk with the villain in a *safe* setting where he’s, or they’re both, stripped of their usual belligerent posturing and do not represent a threat to each other, whether because they’re incapacitated or because it’s not convenient to them to fight against each other in this particular context.
The Force Bond accomplished the above extremely neatly, but there are plenty of ways to get to the same result.
Back in 2016-ish, when we still had no idea the Force Bond was actually going to be a Thing, and after MSW dropped those “leaks” about cliffgate and Kylo & the KoR showing up on Ahch-To and dueling against Rey & Luke, my favourite TLJ headcanon/tentative speculation was that Rey was going to fall down the cliff and into the sea during her fight with Kylo, and Kylo, sensing she couldn’t swim and was about to drown, would instinctively jump and rescue her. Which would cause him to lose his guard and be captured by Luke, who imprisons him in one of the huts. At this point Rey would start visiting him repeatedly, in secret, having grown curious of him / wary of Luke and wanting to hear his side of the story. Cue a series of quid pro quo, Clarice secret encounters between Rey and captive!Kylo where they’d start learning about each other, at first reluctantly, then more eagerly (just like they did in their force skype sessions, but in person). For some reason Rey becomes convinced that Kylo knows who/where her parents are or can help her figure the truth, and she spontaneously asks him to read her mind to look for buried memories. When he does, he realizes that there’s something blocking Rey’s memory of her abandonment, and they both have another taste of that “electricity between” them that first manifested during the interrogation.
This causes them to become even more enthralled with the mystery of each other and their strange connection; they also both conclude they’re linked for some reason---and that must have to do with Rey’s suppressed memories---and... well, the fic writes itself, doesn’t it.