This is my primary expression of my inner girl. I've done it all my life. I've been told that when my best friend and I pretended to be the Ninja Turtles at 5 years old, I would choose to be April O'neil.
When I was in my young teens, I discovered EverQuest, a Massively Multiplayer Online Role Playing game. MMORPG for short, MMO for shorter. That's the first time it became really clear that 98% of my created characters were female. This is the first time I remember feeling like I had something to explain. People asked and being a teenager I went with the "Cuz hot chicks!" excuse.
The same rule holds true to my main characters when I write, with 98% of them being female. I found my favorite characters both of mine and of the fiction I enjoyed were almost always female. It's to the point where my friends and family just assume the girl is my favorite in any cast of characters. The quirky one if there are multiple female cast members. They're usually right.
For me, there isn't really a discomfort with male characters if they are created by someone else. I can play a game with a male lead and be fine with it, although I'd prefer a female lead. For me, the disconnect happens most when I need to make a character. I just can't invest myself into a male character the way I can a female.
As for if this is unusual among cis people? Well, I always felt compelled to explain myself. Sure, my friends and family that play games and such occasionally create characters of another gender, but it's the exception, like males are for me. It's almost always an "alternate" character, and they rarely seem connected to them, the same way I rarely connect to my male characters.
In gaming culture, it's a known "thing," though. Especially guys playing as girls. It's common enough that most people aren't surprised, but there's still a bit of a "weirdness" too it for a lot of people. For some people, it's a downright stigma. It's a common thing on gaming forums for someone to start a thread about how weird it is. Sadly, this often draws the players like this to the defensive, often arguing that "It's not like I'm weird and actually wanna be a girl or anything. I just like how she looks." Sometimes you'll get "I just find female characters more interesting." That one became a go to of mine when I started feeling like a pervert for claiming it was because I liked looking at attractive girls.
Also, because of the boys club attitude of gamers the common perception is that girls don't play video games, and guys playing girls is so common, that the trope is "There are no girls on the internet, it must really be a guy."
Are all those guys secretly trans? Well, I was one of them and that turned out to be the answer for me, and it was an answer that I didn't honestly know for a long time. It's still a bit tough for me to wrap my head around. I know it feels right, but there's all that time I spent telling people that I didn't do this because I wanted to be a girl. I grew up with movies and TV shows like Ace Ventura telling me that would be totally weird, and while no one ever told me it was wrong, certainly no one ever took me aside and told me it was okay. That feeling of "wrongness" is hard to shake.
Even as I grew up, and I felt my mind opening to the idea that maybe it's okay to be weird, and maybe it's not so much weird as it is different anyway... It was easy to accept others, but it was harder to think about myself in that light. Who I am is a recent revelation and it's one I'm still coming to terms with.
So yeah, maybe a lot of those guys have something driving them to want to create all those girls to represent themselves. Still, I think it's dangerous to paint with a sweeping brush. Maybe it doesn't go deeper for some of those guys. Maybe they do just like to create good looking ladies to have at their command. Who knows.
If I were to target a PSA about Gender Dysphoria though, I think people who feel more comfortable playing the other sex in a video game would be a good target.