Carbs in sour apple vs sweet apple !!! ??

Hi Folks,

The sweeter the fruit , the higher the carbs!!!

Is this a true statement?

Many fruits taste much sweeter as they age after being picked.
Bananas and apples are prime examples. Buy green bananas
and leave them on the kitchen counter. After 2 weeks the
bananas become much sweeter than when you initially got them.

My question:

Is the amount of carbs locked into the fruit from the time it
got picked? Or time adds carbs since the fruit tastes sweeter later?
Probably something in the fruit turns to sugar with time.

If time increases the carbs in the picked fruits, then someone should
only eat sour apples (given being out of induction).

All quotes I found about apples don't differentiate between sour or sweet
ones.
However, in some website they said to eat the less sweet strawberries.

Thanks,

J.