tifa is, romantically speaking, emotionally unavailable for a significant portion of her life (teens-early twenties). i’ll elaborate on it below, discussing issues of gender roles, objectification, idealization, and intimacy with it.
nibelheim is a place that upholds “old traditions”, and this includes gender roles. there’s the belief that a woman’s happiness depends on the man she will spend her life with, and tifa, as the sole girl of her generation, grows extremely anxious over the notion; if divorce is frowned upon and considered a personal failure, then she ought to choose wisely— which turns into not choosing at all, both in her time at nibelheim and midgar (but we’ll get there in a bit). clearly, this puts a dent on her ability to make sentimental decisions of this nature.
in small villages, kids have a limited pool of contemporaries to choose from, so it’s almost an unspoken agreement that they should all hang out with each other. tifa plays into this, of course. however, as they all start growing, she starts to notice that she’s not only being approached for being their age, but also for what she could possibly represent: a girlfriend, a wife. tifa is notoriously uninterested in any advances, but, in the spirit of not forsaking the only bonds she has (and can have) in town, she learns to fake obliviousness or gently turn down advances. by this point in time, she becomes familiar with the value and subsequent idealization placed on her. i also think that her own father’s overprotectiveness (out of love, yes, but still a little overwhelming) post thea lockhart’s death informs tifa of the ways men can be kind of... possessive, and she sees that too in other nibelheim marriages. why wouldn’t she be intimidated?
traces of two pasts* mentions: “[Tifa] disliked whenever [adults] brought up how her body looked so grown. There would be someone who sensed her discomfort or resentment, and would try to change the subject, but then it would turn into whom she should be with and things of that nature.” two things to note here, which are frustrations that will further estrange her from romance: 1) her aversion to her body being a point of conversation, which only worsens as her body matures even further and makes it hard to believe her appearance isn’t solely why she’s pursued (hello objectification); 2) just how sick she grows from romantic relationships being such a focus of conversations her way, which, while not ill-intentioned, still make her feel confined. these conversations’ timing coincide with her self-improving via zangan’s training, when her focus is solely on herself and what she’s good at doing/wants to do in the future.
so, ironically, the incessant talk about partnership only drives her away further from the idea, and she certainly gets scrutinized for it as she grows older: “tifa is at that age, she’s pretty/kind/polite, she can cook/clean/tend to ppl/etc, why doesn’t she have a partner?” i think these sentiments are especially prevalent when she lives in midgar. it’s worth noting that she only gets the tools to deconstruct the gender roles she was raised with while living in the city (though obviously midgar upholds some of them too, but regardless, the diversity of backgrounds helps to broaden her vision), but, by then, pursuing or even looking for a romantic interest is… not even on her list (what with running 7th heaven and helping AVALANCHE). she most certainly gets a bit of fame from rejecting all advances her way, especially at the bar, but she can’t help it; she’s so used to being idealized that she’s almost convinced her pursuer will change their mind once they know her better and realize she’s not just those good traits— her insecurities, her traumas, her depression, her temper (which is notably less meek and more volatile than people tend to acknowledge lmao, especially as a teen).
evidently, her teens-early twenties are marked by being pursued the same way one seeks a prize, and in response, she becomes averse to it. this all results in tifa… not experiencing any sort of romantic emotional/physical intimacy when reaching adulthood, and it makes the prospect of doing so all the more intimidating. add to that the dizzying journey she’s thrust into during the main game and, well, there’s no time and nor does she have the headspace to establish a relationship; it can only happen post main game.
* even if the writing is more remake-oriented, there are some entries in "Traces of Two Pasts: Episode Tifa" that i'm going to reference in my main verse (most worldbuilding-related), since there’s enough wiggle room on the more unexplored parts of tifa’s past in nibelheim (and nibelheim altogether). i’m making a post highlighting these specific points soon enough!