Theres a lot of variables to consider.
1. Trauma. (Can impair a relationship, we call this baggage.)
2. Environment & Upbringing (can be controlled and uncontrolled)
3. Behavior and Decision-making skills
4. Mutual expression of interest/disinterest (Communication)
5. Respect & Trust.
6. Transmuting the Past into the Present.
7. Gatekeeping Parents/Siblings
1. Trauma is a big one.
Typically speaking Trauma can range anywhere from abusive parents. Overcontrolling and strict parenting. Instances of sexual assault, abuse, rape, substance-abuse, addictions, etc. All things that leave a deep emotional or psychological impact on that person you may end up meeting somewhere in the future. Trauma also doesn't have some linear answer such as going to see a shrink, or resting your worries in a faith/higher power, or even something like just overcoming it through sheer will power, its like an innate part of the individual and can have some pretty harmful effects in the kinship and relationship landscape. This is largely a reason why a romantic partner would eventually part because they can become encumbered and exhausted in how their partner handles their trauma and projects it into their relationship.
2. Environment & Upbringing stem from basically the home you were raised, and likely the community and school you attended. Many of us im sure grew up off "Disney Channel Originals" and we have this weird perception of what an ideal relationship looks like. In short. Romanticism dude. Pitched to us originally in Europe towards the end of the 18th Century and it's set the stage for "Romantic Love" and our perception of what that looks like in our environment.
Some of us had parents. Some of us had one parent. Some of us had adoptive parents. Some of us had A adoptive parent. These are all important stimulus to observe when we're kids and seeing what a relationship, our first exposure to one would look like, sets our expectations for our own relationships going forward. If your parents were constantly fighting and threatening, you have an even higher chance of ending up in an abusive relationship just based on how you grew up. You'll either be the abuser or the abused, typically whoever you sided with in your parents environment is the stance you'll likely have. Having like a single parent, and being exposed to multiple different partners sets your exceptions in your relationships as a mirror to the single parent in that, you may not like things about this person or that person and you'll move on rather quickly to another potential partner.
3.Behavior & Decision-making Skills. Considering after a while we're all adults, our own abilities to make our own decisions and think for ourselves obviously take over. You can just as easily argue none of these scenarios are applicable to you, and make your own determination of committing to a romantic partner or openly making a choice to not seek one. Balls in your court sway. Shoot.
4. Talk to' em. I'm sure you've all encountered people think you're "mind readers" or say some busted statement like, "Well you've known me X-years, you should know by now." as if to say that excuses you from communicating when things need to be repeated or if one genuinely forgets. Communicating emotions vs thoughts, are two completely different things. A woman hyperventilating over getting ready for an event typically isn't asking for you to "give her advice" on how to calm down, she's likely looking for you to listen or perform an action that is soothing, so she can communicate and articulate her thoughts, because her heightened emotional state is interfering with being able to do that properly. This happens a lot and why in a lot of context stuff disintegrates because no one can catch this communication barrier, sort of like being told "Read the room" you know?
5. Do I really need to explain this one? Don't be an asshole, at least...don't be an asshole thats not funny. No seriously. People are more trusting in relationships once they've gotten a feel for your personality and character and can trust you. Respect for each other is also equally as important, and if you aren't providing positive constructive criticism you'll end up damaging trust and come off as "disrespectful" so things to keep in mind.
6. This one ties into trauma. I'm sure you've encountered someone who shuts down in the middle of an argument and probably retires to their room or doesn't say anything. This is classic behavior from likely arguing with previous partners, a behavior a parent has likely done in front of a child (you/your partner or whoever is the one leaving the room). You take your past with you everywhere and the more aware you become of behaviors you transmute in the present day, the better equipped you are in a relationship to HOPEFULLY make it more sustainable.
7. You guys pretty much covered this, Im in agreement. I'll add this much, compared men, in this society women are far more vulnerable to be sexually assaulted and raped than men are. A large part of the gatekeeping culture of fathers/brothers over their daughters/sisters is for this reason. It's an oppressive element that while it means well, can impair the young girls from really getting to experience a relationship without that oppressive force. I'm all for giving the gentleman nerves to keep him on his toes, but to be barred from contact or communication is a bit excessive and extreme and I'm not not for it.
Closing - If you want to argue some abstract or extremely broad ideology or philosophy or something motivated and powered by religion, the lord, a higher power, etc etc, have at it. If thats what keeps you bound to a romantic partner, by all means, do what you gotta do darling I am ENVIOUS even. Romantic love is definitely a thing, you'll probably see it more in media than you will in actuality to some extent. Can't really say what special about it except for a pretty bad case of "tunnel vision" you get on another person which can detract from your personal progression if you aren't keeping yourself in check every so often. It really only works if your relationship with yourself is up to par you know? All opinions though, thats all I had to say.