I have 3 switches ranging from $45 to $450. The $450 is today’s price, I paid MSRP of $150 before it became very popular.
All my switches support fibre optic output. They take RJ45 Ethernet input from my router, I take the bits from the SFP output of the switch into a Sonore OpticalRendu streamer (I have 3 of these). The Rendu then converts to USB and into my DAC. The last part is where the purity of the solution breaks a bit, but it is not the end of the world. Ideally, a Lumin U2 streamer or X1 DAC/Streamer takes the fibre connection direct into the SFP on the U2 or X1 (owned this before).
Bits are just bits is not what this solution is concerned with. It is the analog noise on the wire that someone posted about earlier in the thread. Fibre optic is made of glass and CANNOT carry this analog noise into the DAC.
Saying all of this, I could not tell a sonic difference between my 3 network switches. Most likely because I am using fibre optic and the analog noise of my cheap ROON core computer and other network gremlins cannot get into my DACs because of the fibre moat.