I used to think my desire to play female characters was a "closeted trans" thing. It's not. I'm definitely a cis gendered male. I've realized, at least for me, it's more of a self worth thing. I don't want to play as something I don't particularly like, such as me, and so I play something as opposite as possible. I'm working on that, tho.
For most 3d games you spend 99% of the time looking at the backside of the character anyway. Lady butts are just better to look at generally.
Additionally in most character creation it seems easier to get a decent looking female character than a decent looking male character. I'm not entirely sure why but most male characters in games look like blocky fuzzy potatoes. When you start getting weird with fashion choices on top of that it just looks like a potato dressed like a goofball. With female characters you can go nuts with crazy hair colors, piercings, and wild fashion choices and it looks more deliberate somehow.
Bisexual woman here, so I agree with you on the butts, but straight girls and gay men do exist.
Okay feminism time. In my opinion, the reason that dude's look like potatoes in video games is most likely because of the gender disparities in the industry. There just isn't anyone that looks at men from the perspective of attraction.
Part of the reason I think it's a little easier to render women is that they typically have smoother less textured skin than men (video game women look like they are wearing makeup even if it makes no sense), and we're only just now getting the graphical fidelity to render realistic looking facial hair or fine stubble in realtime.
Not that long ago making stubble on a male character usually just involved putting an irregular brown shadow on their cheeks which can be pretty indistinguishable from dirt.
Ever since the appearance modding system went in, my Hunter's been pretty genderfluid - I tend to swap from male to female depending on how I feel that day.
I am similarly cis gender, straight male (much to my more fluid spouse's amusement and dismay). I've just found the fem- voice actors to be better. Femshep, the female lead in Ghost Recon Wildlands, etc. Or maybe it's that the brah actors for the male characters sound so consistently dumb. And now it's just a thing I do.