And there will always be audiophiles who categorize all audiophiles into two group - those that need proof and those that don't. If only all in life and audio were that simple.
I "need" nothing, but I observe everything. And the answer is - it depends, what claim, what sonic benefit and what does the data (reviewers, owners) tell me. But most of all I listen and A B when practically applicable. And over many years I've found many tweaks / upgrades yield little to nothing (sometimes the result is worse!) yet the reviews and owners rave about the benefits. It's easy to want to hear a difference in switches (for example) especially if someone is telling you that you will. It's part of being human.
Here's an easy way to tell how much your external network and switch matter sonically - Pick a song, start playing with your ethernet cable(s) connected. Then have someone disconnect the switch's cable to your server/streamer. If your streamer allows continued playing of the song, listen. I bet you'll be surprised. ;-)
As always, Happy Listening!