Usually when people have good results with HIT it's just because they have good genetics. Genetics is responsible for their results, not the HIT.
I remember in the 90's everyone was on HIT. In the late 90's on the internet HIT was what almost everyone was doing. Now people have realized it doesn't work well for most people and higher volume has become cool again.
Genetics take your where you are destined to go. Whether you do HIT or volume training isn't too important.