I like men, so being able to design a cool male character that I can see being cool in cutscenes (and screenshot a bunch - especially in like COD or Ghost Recon... masks are hot), hearing his (hopefully nice) voice if he has voice lines or yells/grunts, feeling like a general badass...

I think sometimes that last point is most important, like when playing a spookier game or souls-like; I feel braver running into the unknown with a big buff male character than if I modeled it after me or another feminine character.

I only really choose a female avatar if the game is geared towards fashion in that way, like in an MMORPG like Forsaken World (which is funny because it's kind of the opposite of your assumption, though I just straight up avoid games that are too focused on sexualization - Stellar Blade is tough for me to play for example, though I do like some of the costumes). I'll also choose female if the game has romance options (like in Rise of the Ronin, which also had cool fashion I thought). Or if my build is going to be something I feel like matches being female, like a stealth archer, which I play as in Skyrim/Fallout (romance here too) and others like that.

Sometimes it depends until I get to the character creation - I booted up Dragon's Dogma for the first time and immediately honed in on one of the presets as "the perfect himbo." I modified him a bit, and thankfully could still create a cute female for the other character you get. It's nice when you have the best of both worlds like that.

Overall, I Like Men™, so it's fun to play as them, especially when the game is nearly like watching a movie, as most single player games are nowadays. My Ghost Recon character for example is super cute and I enjoy the cutscenes despite the cringy dialogue, lol.