I, sadly, kinda feel this. As someone who has spent most of their waking life in some form of jeans or long pyjama pants and has now started making some major wardrobe changes, I did not know how to handle showing my legs.
I understood the phrase "chicken legs". Though that might have been dysphoria fueled.
I was ridiculed once in like 4th grade for wearing "short shorts" and didn't wear shorts again until after highschool. I'm still not super comfortable in anything less than long cargo shorts. Which I understand are now out of fashion as well...
Fuck fashion, cargo shorts and pants are the utility clothing. They look decent, plenty of pockets, comfy as fuck. You can be prepared for a multitude of events at any given moment.
Rock what you wanna rock! If it's comfy, and you like yourself in it, it's a good pick.
I'm the other way around. I pretty much only wear shorts and i never even thought about what my legs might look like. I think it's important to find shorts that fit.
Now that i think about it, i was pretty self conscious 10 or so years ago and only wore knee length shorts, or even longer.
At some point i stopped caring and realised that 3/4 pants look way worse. Now i wear hot pants, i don't give a shit.
Funnily, an ultra cute pair of capri-style leggings(I was not paying attention, just saw my size with a pattern that weren't aimed at kids) were one of my gateways. I've just slowly worked my way up to showing more leg, and reminded myself that all that matters is if I think I look cute in it.