Unless the scooter has been in storage for years - very few of us have had a tire age out.
Our tires wear out - the rear often twice as often as the front.
Rider weight, road surface, scooter type, riding style dictate tire wear.
There are discussions regarding tire replacement based on age of the tire - on the scooter, and even those stored on dealer shelves.
Others point to the age of tires on a great many cars on the roads today. Our car tires are likely much older than our scooter tires! And there isn't tire mahem on the roads! Maybe scooter tires are as over engineered as auto tires? Worn treads lose wet traction. ...
This doesn't seem to stop riders from fretting about shelf life, ozone, sunlight, etc. Even those who never ride in the rain worry about slightly worn treads of a still sound tire carcass.
Just my $.02 on tire age
Stig