Some of them are doing well. The two tallest in the IFBB are Jamie Christian-Johal (6'5") in Open and Pavel Szotkowski (6'6.75") in Classic Physique. Josh Maley is 6'6" but not in the IFBB(yet).
Josh Maley Great Britain men's bodybuilding
Yemi Adefioye Great Britain classic physique
Isaac Francis Ireland physique of men
Natalia Spierings Great Britain women's physique, women's figure
Chloe Pickford Great Britain women's wellness
Nick Hewitt Great Britain wheelchair bodybuilding
Allison Davies Great Britain bikini fitness women