Why don't people on Mount Everest bring tents with them on their summit attempts in case they have problems while descending and can't find camp 4...Seems like the extra weight is worth it?

Answer 1

It may seem that the extra weight is worth it but in truth this would probably slow the climber down and even put his/her summit dream at risk. Even if you did have the tent with you and on the descent could not find Camp 4, chances are you would be too tired or in an unfit state to even put a tent up.