I was watching pro golf coverage on the news and it seems so odd that men and women compete separately - same goes with pro bowling. Just seems weird to me that a game of skill is gendered when you can't even raise an argument that someone might have an advantage because of what's between their legs.
Clothes. It seems crazy to me that men (and often masc presenting enbies too for that matter) can't just wear a dress on a hot summer day without getting weird looks. Or just to feel pretty honestly. Why is something that's about both practicality and self-expression so fundamentally restricted by what genitals you were born with in the eyes of society?
Also, speaking of clothes: lingerie. I have rarely ever seen lingerie designed for men, and even the one that exists seems not nearly as carefully designed as lingerie for women. This makes me sad, it feels like society does not want them to feel pretty and sexy and it's also just unfair to everyone.
(I am focusing mostly on men / masc enbies here because I always had the experience that women wearing "men's clothes" is waaay more accepted nowadays, but feel free to correct me and chime in with your own examples if you disagree!)
I agree that anyone should be able to wear any style of clothing, but I must admit that clothing typically needs different measurements for men versus women (hips, chest, shoulders). T-shirts and sweat pants are pretty neutral, but a busty bosom won't fit in a men's button down shirt and a little black dress will have too-tight shoulders on many men. There's a fair amount of women's-cut clothing that looks like men's-style, but the reverse is sadly lacking.
I'm flat as a crepe when I bind but many men's button down shirts still don't fit me because the hips are too narrow. It's not like I have wide hips either, I'm under 100cm at the widest point of my butt, but if they fit me in the shoulders, they don't fit me in the hips. I can't wear women's button downs either because the chests are always too big and most of them insist on skipping the button between the neck and chest so the wearer has to show cleavage. Ugh. Little gendered things like that in sizing and construction are really bothersome when you fall outside of the binary.
Honesty when it comes to lingerie I think there's just a very small market. I had a drunk conversation with my former roommate and her gay BFF many many years ago and I got this piece of gold from her BFF (paraphrasing) - "it's not about the wrapping, it's about the package" (not penis)
There being such a small market for lingerie for men and such a big market for lingerie for women is a direct result of heteronormativity and gender norms in my opinion. It's not a coincidence.