Are you really saying that different people don’t naturally have different body types? I’m 5 foot 5 and 175 pounds. Based on BMI, I am “morbidly obese”. But I have a 32 inch waist, muscular looking legs and an objectively toned upper body with little body fat measured with calipers - 6 points. It’s not because I am a body builder. I’ve had this same basic shape whether or not I was lifting and I only occasionally been to the point where I lifted heavy.
I’ve seen other people my same height and weight with large stomachs and no tone and with a completely different waist to hip ratio.
That’s exactly what a somatype is. Some people also naturally gain muscle easier. Do you think that if your average person and a top tier athlete train the same amount of time they will have similarly outcomes?