I think you are putting too much weight on the organization rather than the idea and collective it represents. From a very westernized idealized perspective.
Hamas is not this all encompassing high communication stable organization able to surrender tomorrow.
Hamas, or rather the idea, is instead made up of everyone who had a family member, relative or friend killed by Israel wanting to live a good life without the threat or pain of past actions.
One group of a loosely connected collective surrendering won’t materially change the situation on the ground.
