There's still a big difference mainly relating to mass and speed. The stresses imposed by a 2" thick tread cap spinning at a constant 60mph dwarf those of a 1/8" cap spinning at a sometimes 30.

Since the bond strength holding tires together is basically the same, it's obvious that the heavier faster mass is far more likely to pull apart than the thin slow spinning mass.

As I said, in over 50 years, I've yet to hear of a single instance of sudden or catastrophic separation of tread in a bike tire, not even a rumor of one. Talk of it is groundless fear mongering.