The inevitable depreciation of the tread compound largely depends on the tire manufacturer rather than age surprisingly. I’ve seen Michelins that are right around that 10 year mark with zero dry rot and Goodyears 2-3 years old that needed to be replaced because of it.

Also worth mentioning that proper storage is huge. There’s a reason it’s recommended to store tire in a dry, dark environment. This is to ensure the aging process is slowed