Taken literally your statement is untrue. One can absolutely rely, entirely on proper measurements of a dac, amplifier or other electronics to predict how it will behave in use. For example, there is absolutely nothing that listening will tell you about the sound related performance of a purifi amplifier that cannot be understood from its published measurements. This is so obvious to anyone with a basic understanding of electronics that it’s tiresome to point it out. It’s like having to explain what will happen when an apple is dropped from a tree. It’s a fully resolved issue, a solved problem, a problem not worth discussing.