Here’s what I know: there can be inter-component grounding differences (in design or implementation) that exist when a system is hooked up normally, assuming no issues with power in the room. I experimented (a fairly long time ago) with that Granite Audio device that allowed you to change the relative impedance among 3 different "channels" of external grounding cable-- essentially a star ground-- that did reduce (or seemed to) some of the noise of the system, but did not eliminate a hum from my amps, which are known to do that. (You lift or use one of those humbuster thingies). Yeah, I know, good design and all that, but yell at Vlad.
This was before the commercialization of fancy ground boxes, like the Entreq and Tripoint, which I never experimented with.
My power set up in this house, as of mid-2017, is very good as is the "dirty" power coming to me from Austin Energy. Though I spent for a big iso transformer that sits outside in a weatherproof NEMA cabinet (400 + lbs) and followed best practices in 10 gauge dedicated lines, I’m not sure how much difference star grounding would make. I did have the electrician wire a "clean ground" which ties back to the main system ground, and ultimately, to the house ground (per Code). But I'm not currently using that for anything and when I experimented with it--connections made to a heavy copper buss bar---it didn't seem to make much difference, so I undid all that extra wiring. Maybe that small reduction in noise is improved with the granules in the grounding box, and other esoterica, but I never made that leap.
I think so much starts with the quality of power coming in, and the state of your main service panel and how you are wired in, that I would take the view of sorting that first, before addressing refinements. I know back in the day, ground lifting was common, but I have managed to refrain from doing that.