I think that is normal length for men's hair. Mine grows to a similar length.
Discussion
Wait but why does it stop? Just because it thins out and breaks off etc.?
Everyday, you shed hair. As your hair grows longer, more long hairs fall out.
Then it reaches a balance point where the amount of long hair loss counteracts the growth speed of your hair.
I read in to it once and I found that everybody’s hair has a natural length that it stops at? But I also just am rough on mine so prob could be longer