Brake balance adjust in race

After Watching some flying lap onborad video I find that drivier are very busy on using the brake balance adjust, like 5 or more times a lap. I wonder if this kind of adjust it just as natual as gear shifting or it's just for flying lap ?
In game I only adjust when practicing for car setup, or If my FF car have some badly worn front tire during race

 

In formula 1 they do it in every lap during the race. It's a "easy" way to change the balance of the car on the braking zone.

I saw Hamilton doing it at COTA (us gp) : more front brake for the big brake at the end of the straight line, and more rear brakes on the rear for the quick left-right turns that follow. He was doing during all the race according to it's on-board cam