Putting a retread on a worn out tire carcass, is a recipe for disaster.
Shortly after the Second World War, a new tire cost maybe $15, or you could go to a “recap shop”, and put new treads on the old tires for maybe $5. As long as not too much stress was put on the retreads, there were serviceable for a few thousand more miles, but eventually, the tire would fail altogether, either by the sidewall bursting, or the tire tread coming off as a strip and going WHAP-WHAP-WHAP on the underside of the fender, before falling off completely, and left on the highway as apparent road-kill.
Retreads are no longer legal for passenger car use.
Was a time during the fifties that no road trip was complete without seeing several recapped treads along the road.
We refer to retread "leavings" on the roads as truck boogers.