I suspect that almost all singles in FIRE community considered (=dreamed) at least once about having a romantic partner interested in FIRE. And I suspect that people with non-FIRE romantic partners (especially when they have different views about money) had this thought more often. I am not an exception. I myself was in a relationship, which happened to not work too well. FIRE was not the only reason, but mustachianism had uncovered many differences between us. Ultimately it was good in the long run, but in the beginning it was a frustrating experience for both of us.
So let's look together what having a FIRE partner brings:
You can actually FIRE together and probably even sooner (TODO: mention my fire together calculator and financial considerations of firing together post). FIRE'ing together sounds so cool. First, you get another person to build your plans with. So your plan becomes at least twice more robust (the precise number is just a joke, but diversity of views helps with robustness for sure). Moreover, you can actually share some common expenses like an accommodation and speed up each others path to FIRE.
When you two actually reach FIRE, each of you has at least one person to spend your new free time with! This may seem trivial, but this is a huge deal. Let's say one person in a relationship FIREs at age 40 and the other person just works until ordinary retirement. This means that for 20-25 years, they won't see each other ~35% of their awake time (assuming 40 hour work week). It is also hard to imagine only one person FIRE'ing. Let's say you pursue FIRE and they don't. And eventually you FIRE. And they don't... This seems hard for me to imagine. Basically you having a bunch of free time and they still having to work. I see two ways this could develop - either they become unhappy with the situation ("they probably don't care about me enough since they have this free time and I have to work") or you feel sorry for your partner and sacrifice your position to make their life better. There is nothing wrong with any of this, but this is a huge conflict of interest for both of you. Perhaps my imagination is just not good enough, but I struggle to imagine only one partner FIRE'ing.
They are more likely to be responsible with money. Somehow modern society has got this idea of "life is short, live fast, spend a lot like there is no tomorrow". I am not saying this is bad per se, it is definitely a choice of each of us what to do with their life. I just wouldn't choose this lifestyle myself. And I obviously wouldn't want my partner to be like that. While some difference and diversity in a relationship is good, this difference seems to be especially painful and conflicting. Also many women who use firedating.me mentioned this as their main reason for using the website.
They are probably more like you in general. Interest in Financial Independence is quite a filter. If you both get through it, you will likely be much more similar than with just a random person. You probably have similar views at money, gratification postponement, work, free time, life planning. You also speak quite a common language already. There is at least one topic you can discuss. You are also probably more likely to tolerate different, unpopular or extreme views (FIRE is an unpopular extreme view). So I speculate that building a relationship with a FIRE person might be easier. No concrete proofs here yet, sorry (not even anecdotes to be honest).
I am pretty sure that I didn't convince you that it is worth trying to find a partner interested in FIRE (because you knew this before). Obviously, finding one is a much trickier problem, so I will share my ideas how to do that (TODO: add link to that post). Spoiler: at firedating.me there are many people interested in Financial Independence who look for romantic relationship (also many are looking for friendships).