When I was younger, I don’t ever remember being conscious about my eyebrows. There were much like the hair on my arms, just there, and basically staying the same length.
However in the last 5-10 years, I have to trim my eyebrows about every 3 weeks or so. The hairs are long enough to some of the hairs grow to over an inch long.
I have noticed many older men with very long eyebrows. Kind of like this guy. But I don’t think I ever see a young guy with really long eyebrows.