The catalogue is a work of art - incredibly detailed information about every artist and album, lyrics for most. I know a lot of other streaming services have good info about the things in their catalogue but, as has already been mentioned, these catalogues are volatile where Roon's catalogue doesn't carry the risk of being pruned at any time.
There are two main meanings of the word "audiophile". It can describe 1) a person whose music playing experience involves more than just the default music player app that shipped with their phone, and/or iTunes, and/or Spotify. It, much more commonly, also describes 2) a person who buys diamond-coated gold CAT-6 Ethernet cables, because they make the zeroes rounder and the ones straighter as the bits travel from their computer to their $2000 preamp, tuned to inject noise that makes the music sound just right.
OP is definitely 1), but I think they also want to make sure they're not confused with 2).
The hard upper limit is the equipment the mastering engineer used to listen to the track when mastering it. Even if your equipment can reproduce more detail, that's likely unwanted detail.
Something you'll frequently notice when listening to youtube shorts on a big home theater setup – a lot of wind noise below 80Hz which the author couldn’t notice, but which is deafening. The same, though more subtle, happens when listening to professionally mastered audio with an excessive audiophile setup.
If the track you are listening to was recorded in some teenager's bedroom on a crappy cassette deck, then it should sound as such. This is equally as important as being able to pick out the detail on a track that has been produced with all the latest state of the art equipment.
Music is fundamentally about communication of emotion that transcends language and the purpose of a good HiFi is to facilitate that communication.
However, when it comes to consuming things like video content, particularly that made for youtube, tiktok, etc. then it is probably unfaithful to even attempt to listen to it on a high-end system, just as you say. It's like eating MacDonald's in a michelin starred restaurant or scranning gourmee steak from a takeaway container while drunk on a street corner at three in the morning: context matters.
See also: https://hard-drive.net/hd/entertainment/100-gecs-song-blasti...
If you've spent all of the time and effort to put your audio collection on local storage that's also encrypted and mirrored, you are the audiophile audience!
Roon is a great option. I don't really understand OP's objection? Roon supports over 800 different playback devices in addition to software so it's pretty unlikely you don't already have something that supports it.