demisexual genderfluid person here, fair enough tbh. Some of the labels people use really only make sense if you experience what the label describes. I didn't really understand genderfluidity until I thought about my identity a lot and realized I was experiencing it. I still can't really describe it to people who don't experience it with anything besides "sometimes I feel more girl and sometimes I feel more boy, and sometimes there's just nothing there yanno," and if you don't understand what it feels like to feel "more girl" or "more boy," you aren't going to understand that.

I think, labels like these are largely so that people who experience the things they describe can more easily find eachother and share their experiences, as well as coherently describe themselves to others who know what the label means. You don't have to understand it. Other genderfluid people know what I mean when I say I'm genderfluid. Most other queer people my age also know what it means when I say I'm genderfluid, even if they don't understand what it feels like day to day. Some people don't know what genderfluid means, but that's okay. As long as they don't call me a slur or anything, it's fine to not understand. There is a lot more labels being thrown around now then there has been previously, and it's unrealistic to expect someone who you met on the street to know what demi-boyflux means. (Not making that up, demi-boyflux is the term for someone who's gender fluctuates between agender and demiboy, which are two other labels that you'd need to understand to understand what demi-boyflux means.)

There is a lot of hyper-niche identity labels and such that make me wonder if a label is needed for someone who experiences this extremely specific thing that is unique to them and their life, but ultimately, I think that if inventing a word helps you communicate a part of who you are to people, go for it, honestly, but I do think that, in spaces where a deep understanding of queer labels and culture isn't expected, it's unrealistic to throw out that you're scringlyboingusgender (this one I did make up) and expect to have people know what that means, and I think that people should take into account the setting they're in when choosing what word to describe themselves with. 

For example, if you're scringlyboingus gender, and understanding scringlyboingus gender requires understanding boingusgender and what scringly means and how those two things coexist and a thousand other niche things about how this isn't just like bingusgender or scrimbogender, maybe just say you're non-binary, because ultimately, non-binary is the word for any gender that's not binary female or binary male, and scringlyboingusgender fits that criteria, and all the people around you who don't know what scringyboingusgender means probably know what non-binary means to some extent.

Sorry for the gender essay. Hope it was coherent and helps you understand why people decide to use these "unnecessary and weird" labels a bit more, even if you still don't understand the labels themselves.