Just to share another experience, over here from Europe.
I can confirm that running a fiber cable from ones internet router (as in my case via a Ubiquity ethernet switch with a fiber uplink) to your audio room, already makes a substantial improvement over the 15 feet cat6 standard cable that I had earlier. It connected into my Innuos Mk2 Roon core/server via a fiber/ethernet converter that I used for this, which in turn was fed by an Sbooster Linear PS.
Recently I was offered the chance to test replacing this converter and PS with a Cisco Meraki MS-2020-8 switch which was 'reliefed' from its own internal power supply, and teamed up with a Plixir Elite Balanced DC power supply by someone here in my home country, who also threw in a home made specially shielded short ethernet cable to connect the Meraki switch with my Innuos Mk2. The improvement in refinement, dynamics and overall image opennes that this delivered was mind blowing.
Last night I took the same Cisco Meraki switch plus Plixir BDC and short ethernet cable to a friend where we tested this setup, but this time fed by his 15 feet Cat8 standard cable (so no fiber) and still the improvements where astounding.
I have no personal affiliation with neither Cisco or Plixir and hope to have given a purely unbiassed experience.
Enjoy the music!