straight women won’t date them

You can be straight and date someone who is trans. Genitalia is only one part of a person's body/gender, intercourse is only one part of sex, and sex is only one part of a relationship. (and for some, sex isn't even part of a relationship)

When it comes to relationships with queer people (which, to be clear, I think is everyone to some extent), you gotta first think of sexuality and gender as a spectrum, because if you're thinking in traditional gender binaries, there just isn't a good way of explaining many things.

Trying to fit gender non-conformists and different sexual orientations into a hetero-normative binary is like taking the visible light spectrum and then trying to describe it in terms of black and white. It's at best going to be a very poor representation of what's actually there that doesn't get you any closer to actually understanding things.

This is one of the articles I sent my brother to help explain things to him, hopefully that helps reframe things for you in a way that's helpful in understanding things better.