More drama than information. If your buying used tires, or tires at the local gas station, then there could be a big issue. If your buying tires from a tire distributor, typically they/we will just about give the tire away once it has sat on shelf for 3 years.
Tire life will depend on where its parked, how its driven etc.. there is no magic number, better quality tires can last well past 10 years after manufacture date, if stored out of direct sunlight (on or off vehicle) and not over heated.
There are tires that come apart in less than 3 years.
Industry average is start suggesting people replace 5 year old tires, and if there is a tire that is in the 8-10 year window, suggest replacement on time.