Why do people insist that streamers make a change?
My guess is that virtually all of these anecdotes come from sighted listening tests which are prone to psychological biases. I don’t doubt that these listeners perceive a difference, it’s just that the outcomes or their tests aren’t very reliable.
So given the lack of reliable subjective evidence, the only evidence we can use is objective measurements. I haven’t come across any data that conclusively shows that a modern bit-perfect source (e.g. streamer) makes an audible difference in terms of distortion, noise, frequency response or jitter with respect to the USB interface - link.
In any case, you can test this yourself by having a friend or significant other switch out something in your playback chain without you knowing. Then see how many times you’ve detected a change. If you get it right 9 out of 10 times, it’s most likely making an audible difference.