I can say with absolute subjective certainty (see how I wrote that?) that all the things you read about that you can do upstream of your music server and your DAC will make a noticeable and additive improvement...in a wired environment. Optical isolation, linear power supplies, power filters, dedicated power lines, bespoke ethernet cables (research brands), USB cables (research brands), USB reclockers, 10 mhz clocks, 75 ohm BNC bespoke clock cables, 50 ohm BNC bespoke clock cables, bespoke switches...all make a contribution to an improved system. Ultimately noticeable in terms of black background (did my system just stop playing after that song?), bigger soundstage, and smoother more realistic vocals. But it's a lot of money and clutter. A lot. Would you be better off taking all that money and upgrading speakers, DACs, amps, preamps, or music servers to the next level of each? Perhaps. Welcome to the debate. But tell me none of this matters? I will emphatically say back to you, you're wrong...everything matters.
I don't know what the right answer is from a $ perspective. I don't. Sometimes I lay awake at night and care. Sometimes I don't and I sleep like a baby. Sometimes in my listening chair.
It's also nice sometimes to pull out the H2Go, wirelessly, taking advantage of very little of all that clutter, sit outside on your patio, appease (somehow?) the H2Go wireless Roon gods, and entirely get through one of your all time favorite albums from your younger, healthier (happier?) days, and nothing else matters.
Mania.
P.S. A bourbon can help in all of the above situations. YMMV.