Do you usually go to failure on all your isolation exercises?

I pick the biggest weight I can lift and go for 7-9 reps to absolute failure for isolation exercises for all sets on any given day. Bicep curls, Chest flys, tricep pushdown etc.

I am exhausted by the end and in the last set I will only be getting 6-7 reps in the set. Is this optimal for hypertrophy or am I going too hard and should reduce the intensity and rather focus on more sets/reps ?