I came upon someone having said that individuals' inherittability is different and for ex, some people's inherittability is strong so that the possibility of their children inheritting their height is way higher than those whose inherittability is much lower.
Take my paternal grandparents for ex. As my father said, both of them were short and my grandma was even only 143cm or so.
They had 13 children! Yeah you see it right(therefore, my grandma was a 'glorious mother'. Yeah I come from China and China is always eccentrically obsessive with fking reproduction but having 13 children is even extremely outlandish in fking China).
And only my 8th uncle is 170+cm, while all of my other uncles, including my father, are either around my height or even shorter than me(162cm), and all of my aunts are like below 150cm. So clearly it is my grandparents' genes that caused me to be short, and as I learned, they had high inherittability.