Are all streamers the same?

Dogma says they’re all the same. Experience suggests otherwise. Price may or may not be guide. Are there solid tech reasons such as bleed of noise into the digital signal? What does “it’s all about the ‘implementation’”really mean? How come power cords and interconnects make a difference? For example, there are numerous USB cords that separate the power from the signal cables to minimize interference and noise transference.

Why don’t we have an accepted science of audio, as yet? Where’s the research compilation esp at textbook level? Yes I’m happy just listening and using my ears and my biases to make judgments; no problem.

Yet I continue to see dogma, from the USA and Europe, indeed everywhere, that remains steadfast in their disbelief in variances. It becomes tiresome at times. But hey what do I care? Lol, my pursuit of fidelity and knowledge remain equally strong.