Before sitting toilets people had to squat to poop. Everyone could atg if they take the time and effort. Ofcourse you if you never did this before in your life you will have difficulity and u cant change that in 1 workout but eventually you can. I am talking to normal people here by the way not disabled people.
There is a huge difference between shitting in the woods and squatting with heavy weights on your back. Ask most non trained people to squat down to the ground and their heels come up and/or their back rounds excessively. Lower back rounding is a result, most of the time, of the neck of the femur hitting the hip socket because there is simply no more room in the joints to flex your hips. Having that happen when shitting in the woods or sitting into it is fine, but that repeated bone on bone contact with heavy weights will most likely damage/hurt your back and/or your hips. That's why you see anterior femoral hip impingement exploding after crossfit became popular.
Yes, hip sockets matter. Here's some anatomy for you. Femur neck angle, hip socket depth, hip socket angle and so on will all effect the room availiable in the hip to do flexion before bone hits bone.
This is a very rough generalisation, but Asians and Eastern Europeans
tends to on average to have shallower hip sockets with more anteverted femurs, meaning they have more room in their hips to flex and can achieve greater depth without any problems. Nothern Europeans and Germanian ancestry
tends to on average have deeper hip sockets and more retroverted hips resulting in the reverse. In reality though, individuals differ.
Again, squatting ass to grass is fine when you're shitting in the woods or just doing BW/light load stuff, actually it can be beneficial. However with heavy weights some people really shouldn't.
