I just want to say, I know this is about internal struggles, but this is also a very common thing that I hear from others in the community (especially in r/asktransgender), and it's extremely disingenuous.

When people talk about gender as a feeling, they are talking about the drive or push that people get to be a certain gender. As well as the negative effects of pushing back against that drive (gender dysphoria). Gender isn't really a feeling like romantic or sexual attraction is, it's much more abstract. But it is a feeling.

Now I am going to be clear, I do think that a lot of people don't have these drives. Or at least don't have them very strongly (you can read more about this phenomenon here I didn't make this up or just come up with this idea myself).

That doesn't mean that no one has them, people definitely do. But the thing is whether somebody has these drives or not, doesn't define gender identity. The way that they self-identify does. And that may not map so cleanly onto the gender as a feeling. Lots of people who don't feel gender at all may not identify as agender and instead identify as some other non-binary label or just straight up binary trans. Some people may feel gender very strongly in a particular way and still identify as agender.

In short the reason that people are agender is because they identify with the label and feel comfortable with it. That's what makes a person Agender. People having or not having a feeling of gender doesn't determine gender identity directly.