Bi= two. You can use a hammer bar to work your side biceps.
I don’t care so much about muscle hypertrophy at my age, but I don’t want my lower arm to keep waving when wearing short sleeves and I wave goodbye to people, then stop.
And doing pull ups will work those arms, traps, lats and intercostals. An isolation exercise for overall muscle development makes no sense. Squats, deadlifts and pull ups are the best three exercises you can do.