The last time I have tried the diferences and post it here was on November 2021, today I have tried the same, installed audirvana origin on the same server that runs Roon, also have bubble upnp running on the same server.
My findings are the same, on a Naim NDX 2 the only change was the software not the server, cables or network path, only the software. Audirvana and Naim App serving audio files to the NDX 2 sound better, more clear and with more air than Roon, roon appears to have a filter that degrade the music a little and also clarity, air and the music feel less resolved and more two dimensional. The other two loose on the user experience and interface is not as polished.
So after five years I still use Roon because of interface and multi device support, I still find that sounds worse than other apps, is a subtil change but not difficult to notice on some systems.
I have never noticed even slightest difference between Roon and any other source/server I use when I compare audio quality. Zilch. (Regardless of CD, Qobuz, USB, MinimServer, AssetUPnP, Roon, whatever I throw at my HiFi setup, if it’s the same master, it sounds the same.)
I would find it alarming too, because a difference in sound quality would clearly mean some setting somewhere is not correct.
I really loved the Commodore 64, never had one unfortunately, but I had a lot of commodore Amiga computer generations from the Amiga 500 to the 4000 tower, they were great machines at the time, sad the brand did not survive.
More of an Atari person myself, but those were good computers for their time (or ahead of their time, for Amigas).
The point though being that unless one is trying to do some very complex DSP and is just pushing original bits, any modern computer running non-broken software will do exactly the same. Computers are deterministic machines and no magic happens inside…