So far, the US has failed to achieve any objectives obviously worth the costs of the war. Iran is still unfriendly. Iran hasn’t agreed to any long-term commitments. They still have the ability to strike death and terror in the region and to damage the global economy.
If regime change or a long-term commitment is not going to be reached, then continuing to mow the lawn is likely not worth the costs, so it’s better to quit now than to take further costs. But, quitting now does mean the US failed in anything but destroying a bunch of stuff. Iran will quickly rebuild their drones and missiles and remain a terrorist state.
Let’s see what negotiations result in.