There's several different scenarios where a structured settlement is very important, very helpful and serves as a useful function. The first would be in a settlement of a case involving a minor. Remember minors aren't given money in a lump some when they are under the age of 18. Typically most judges are not going to have that money coming to the minor's hands until they are at least 18 and many will allow the structured period to go on beyond their 18th birthday.
The second would be someone who may not have, because of an injury, the ability to handle their money or may need special care over a long period of time or need financial support over a long period of time. So a structure might be setup to provide monthly benefits, quarterly or annual benefits. It may payout medical expenses for them at certain designated times. It could put them through college. They conserve any number of functions to provide for someone who can't handle the money themselves or understands in their own mind that it would be best to put the money in the hands of a third party.
And finally, it might be someone who has the ability to defer, put off receiving the money. Someone who could put it in an investment that would fund their retirement which allow them to either retire fully or do a partial part of the retirement many years later. The longer the money is left in the structure the more it is allowed to grow.
These are sort of the classic examples of when a structure will be used but they can be used in anyone's situation to serve whatever is best to preserve the money and make it available for what's important for them later in life.