Digital is about clocking and power supplies. This is where switches and USB reclockers come in. On Ethernet, the fibre route works up to a point since it doesn‘t suffer from EFI/RFI noise incursion. Alas, the converters themselves aren‘t the best time keeping devices and create distortions of their own. Ethernet can be made to work, but only with a lot of effort. In my case, I employ three switches with associated linear power supplies after the router. The router, which only has the system as client and its own LPS is followed by a simple Netgear router after a 25ft line, this in turn is followed by a LHYaudio Ocxo switch which I can‘t recommend highly enough, which is again followed by an Etherregen, which is clocked by a Antelope 10m clock. Power supplies are LHYaudio and Sean Jacobs for the Etherregen. From the LHYaudio switch onwards cables are 50 cm in length and top quality cat8 throughout. This setup is the result of 3 years experimentation
And btw: on the USB link reclocking and galvanic isolators are required, again with LPS.