But I generally know the dates far better than any AI could guess (based on ages of the individuals I know).
If it doesn't know the month, it puts it in June. If it doesn't know the day, it puts it on the 15th. But yeah, old photos with EXIF is more to be used by putting them in an order of photo1 comes after photo2, etc. Not necessarily photo1 is exactly 1982, etc. Viewing and enjoying old family photos is more about the order, and less about the exact year (at least for my family and friends).
At least the scan date is a real piece of data that could be useful. This seems like it would cause more harm than good by polluting the data with nonsense, unless the added dates are clearly labeled as estimates
The way to increase the accuracy is to add a birth year to face tagging so each photo has an anchor that the AI uses -- "This photo has joe, joe is born in 1950" and then it will look at how old joe is and if joe looks like 10 years old, it knows the photo is around 1960.
Technical background.
You can tag faces and add a birthdate; so sort of. Like it'll recognize a birthday party photo and then if it's tagged with that person in the picture, it will date it on their birthday.
doesn't handle 80's themed parties very well.