a remarkably basic question about Roon

If you haven't tried ROON it might appear to be unnecessary, but once you have used it for a few weeks and discovered what it can do, you will want to keep it.

Just noting the OP said the music was louder using ROON, i found that reducing the ROON gain into my pre amp improved the SQ.

You can also buy third party "ROON Nucleus" servers running a dedicated Linux software which are much cheaper and just as good, as the official version.

These servers only use SSD memory so produce no noise and you can add a LPS as well, making this a very high end streamer and DSP engine.

I have found using ethernet cables to send the bits (from the ROON Nucleus) to my DAC was much better than USB. etc and then adding an audiophile network switch ( and LPS) and re clocking brought out further detail.

I like Roon a lot, but there is one PITA issue if you use Tidal. Playlists in Tidal can be imported to Room, BUT not from Room into Tidal. So, if you build Roon playlists & only stream at home where your core server is, all is good. However, I like to stream when driving, where Tidal works, but Roon doesn’t.  What that means is if you build playlists in Roon, there's no way to play them when driving that I know of.

Generally speaking Roon is worthwhile. I like the articles on music and musicians, as well as the arrangement or curation of my library. They do have a lot of software glitches. If you have a big music library that is well organized on your MacBook or whatever I don’t consider Roon to be necessary. All in all, it is something of a luxury, but nice to have.

I held off on streaming fir a long time because I didnt know where to start.  Small Green Computer kept coming up and I called and talked to Andrew Gillis who has his own line of music servers / Roon cores and also sells the Sonore rendu products as end points.  He had me up and running in just a few days and provided great remote setup.  I use Roon / Tidal Masters and have never looked back.