heyhey i'm new here!! go easy on meDom Fi + Ne/Si certainly has its weaknesses, but like OA said, I think that Fi is a fairly misunderstood function in the sense of how it works as a Judging - analytical and weighing - process. It gets a reputation for being fluffy or oversensitive, as what people do not tend to see is the intricacy of thought and strength of value going into our judgments. They can't get inside our heads, after all, unfortunately for them.
And, while Fi might be a unique challenge to deal with in a partner (as if some others aren't... Fe? Ti?!? ), I think it also has a particular strength in a relationship when it comes to gauging the holistic wellbeing of the pairing as well as the individual wellbeing of each participant. We have an especially good "radar" for how each person is doing and for what can be done to make them feel more fulfilled and whole.
I also do think what others have pointed out about NFP idealism is true as well... We are hard to please, plus Ne makes us exploratory. That can yield an internal challenge to be happy with reality and without seeking something better. (I do think probably some of the inadequacy feelings are a 4 or 4w5 thing more than an MBTI thing. I have a bit of a different set of concerns as a 6.) At the same time, speaking of Fi strengths - I think we are less likely to misread the quality of someone's character. We probably tend to avoid some of the pitfalls other types can more easily get caught in, like staying with someone who is unsure they want a relationship. One of the qualities of Fi is to be more unyielding, and less likely to allow violation of our wellbeing. I say this because I have a few friends who are feeling the impact of giving a bit too much leeway in their relationships right now... And I think those situations are something IxFPs are far less likely to find themselves in.
As for reddit... I think take any compilation of opinion on the internet with a grain of salt. When I was exploring careers, I developed a (bad, in retrospect) habit for a while of researching people's career experiences online. They seemed to always be overwhelmingly negative. After becoming increasingly terrified of everything I was researching, I realized that this probably has more to do with the internet than reality. It's a place where you can freely dump venting with no consequence. And the people who are happy - with their careers, with their relationships - are less likely to be venting online and more likely to just be living and enjoying their lives. Internet opinion tends to be skewed negative.
My final thought is, at least for myself, I have discovered that it is my pattern in life to tend to take longer than average to get around to things. Reading... Writing... Peer socialization... Choosing a major... I tend to hold back and observe for a long time. But then, when I do enter the fray, I tend to do well. Relationships have been no different for me. I didn't enter a serious relationship until my early twenties. Now I am a little more than three years into it and still very happy. So no, I do not think it is impossible for us to find fulfilling romantic love.
I do agree, however, to being hopeless at double posting.
what is the MBTI type of your partner?