In my family it was a matter of heredity. It all came from my fathers side and strangly affected the boys the most.
My father and my uncle and aunt wet untill they were 12. All of my cousins untill we were ten or twelve and all of us were in cloth diapers. This was the 1950's there no disposibles.
Family gatherings were different than most. At bed time we would all get our PJ's on and go to the living room. We were lines up on the floor and diapered assembly line fashion. And this was done by whom ever was available. Grand parents, parents, aunts, uncles I have been diapered by all of them.
We were all expected to be in diapers but NEVER were any of us punished for bedwetting.
Usually between 11 and 13 we would start to dry up. Once we were dry for two weeks running we could ware training pants. If they stayed dry for two months we allowed regular underware or just PJ's.
Yes there were occasional accidents but unless it was repeated we were not put back in diapers. Not needing diapers was met with congragulations from the adults and a certain amount of awe from the younger ones.
As we graduated to the dry side we were also expected to help (both boys and girls) with not only the diapering but the large amount of laundry six kids in diapers generated when we had a family gathering at my grandparent's farm.
My own girls were examined by doctors and given medication to help. By the time they were five they were out of diapers.
My granddaughter was trained by three. So perhaps it is no longer in the genetic makeup.
In light of this I find punishing kids for bedwetting apprehensible.
To me there is usually a reason.