AMD started out and get the designs directly from Intel to make 8086 CPUs on license and continued onto the 286 until Intel broke their agreement and they had t

AMD started out and get the designs directly from Intel to make 8086 CPUs on license and continued onto the 286 until Intel broke their agreement and they had to make clean room 386 implementations. So AMD has been doing this since, essentially, the beginning, and have been able to iterate tracking Intel and not starting from scratch in the 2000s with an entirely new approach. They probably could have done it, eventually, but they ran out of funding and thats the end of the road for that adventure.