Eating old fruit is safe as long as the old fruit has not actually gone bad or the old fruit does not have any mold on it.
If the old fruit has gone bad and smells or tastes bad then eating the old fruit could make you sick so you should throw out any old fruit that contains any mold or has a bad smell or bad taste to it.
If the old fruit is mushy then it may also be bad and should be thrown out to prevent illness.
But as long as the old fruit has no mold on the fruit and the old fruit does not smell bad or taste bad then it's safe to eat it.
Fruit should be eaten well before it has time to go bad because as fruit gets older it tends to lose some of it's vitamins and nutrition.
If you need to keep fruit you can cut the fruits up and place them in freezer bags or even freezer safe containers and then store the fruit in the freezer.
Freezing fruit can make the fruit last for up to 6 months.
But fruit is more health beneficial when you eat the fruit when it's fresh and not frozen.