RR, It may be just me but it seems like tires that "Sit" are the problem ones. Not so much on daily drivers.
I do keep a close watch as they get older.
We have intense heat and asphalt temps can be 180+ at times.Concrete on the same day maybe 20* less.
My daily driver PT tires are 7 years old and scheduled for replacement next month. ( Built in annual budget) Total mileage a little over 45,000.
They look healthy but for me the heat is coming up fast. Don't think I'll chance it.