Oyster shell has been plentiful and cheap for many, many generations. I'm sure some of our grands used it.
As others have pointed out, there are many sources of dietary calcium for chickens besides shell. I'm not sure when commercial chicken feeds first became widespread, but it can't have been terribly long ago that chickens either ranged free or were fed table scraps including eggshells and small bones.
We'll give our chickens oyster shell because it's cheap and readily available, but I suspect their diet already has plenty of calcium because they free-range much of the day and have all the bugs, worms, dirt, etc. they can catch. (Not that the dirt is all that difficult to capture...)
I'll find out once they start laying. That will probably be in November, so they probably won't be wandering the yard much beyond then and we'll give them oyster shell. We had a couple of feet of snow in the yard from December through April last winter.