My opinion of tire date codes...really no difference than date codes on all of the packaged food products at your grocery store
Tires still have organics in its material list
“Organic” decomposes over time...meaning it rots over time. Package food has much controversy over “preservatives” added by the manufactures to extend the date codes...tires likewise and can be deadly if eaten...my guess
IMO...tire OEMs have varying blends of anti-rot chemicals and the why some have differing opinions of their tires longevity...or not
Also, IMHO, the why some that looked ok, but fell apart.
Tires see EVERYTHING before the rest of the vehicle...meaning that they are first to hit that rock, pothole, curb, etc...and within that tire are fabric cords/weave (some are metal) the main thing holding the organic material together...break or compromise those cords and a weak point...AKA stress raiser for later...
I drive VERY hard, so my tires get used up before their date code time limit (set by industry). Though I don’t drive the Sub as much, so this a reminder to myself to check those tires more often...
Edit...main reason for the use of 303 on all of my tires, including bicycle tires. Inside and out side before they are mounted and often during the years of use