Any good theory probably needs to explain or reinterpret past phenomenon that has already been proven by experiments under the previous paradigm. Part of what

Any good theory probably needs to explain or reinterpret past phenomenon that has already been proven by experiments under the previous paradigm. Part of what made Einstein's theories so good is that they reinterpreted past theories while providing new explanations that fixed major unknowns in the science of the time. Both for GR and QFT.