Why would I need Roon?

I don't know that you need roon but the reason I got roon was the user interface and sound quality. In my subjective opinion as I never tested blind is roon has better sound quality over my Node2i, both with my ripped CDs and Quboz. I like the user interface a lot better and the fact with roon I don't really need a dedicated streamer. I let the core handle the streaming and use a roon bridge with RAAT to connect to my DAC. The DAC controls the clock of the stream and IMO gives me a nice simple solution with excellent SQ. 

I’d try Audirvana if it would run on an minimalist OS designed specifically for music playback instead of windows or iOS. That could be why Roon sounds better to me.

I do send it to a raspberry pi4 running Ropiee as a bridge. I use ROCK on a NUC for the core running in my office. The difference is I can run ROCK headless 24/7 , it's optimized for music playback,  self updates and I don't have to mess with windows. If Audirvana could run on a small linux distro headless I would try it but I've never cared for any music programs I've tried with windows. Roon is much simpler and I find the SQ superior at least the way I run it I didn't when I tried it on windows. 

If you simply want to try Roon install the core on a computer and it should find your Node2i as an endpoint. Keep the Node2i connected as is , install Roon app on your control device and play once a few simple steps are followed. You don't need to get into DSP, EQ until you get comfortable with it. 

It could be because I’ve assembled computers and installed OS’s that roon seems very simple to me. When I say roon sounds better to me than other player software it’s a purely subjective opinion, I’ve never done a blind listening test. I think the main reason I feel it sounds better on Roon’s OS, ROCK is it doesn’t interfere with updates and running other processes in the background. Music not suddenly stopping for some unknown reason. ROCK is an extremely small linux OS designed by Roon specifically optimized for Roon playback. I assembled a NUC for about $600 installed Roon core and connected it to my network. I assembled a raspberry pi4 running Ropiee which also uses Roons transport protocol RAAT as a bridge and connected that to my network and to my DAC by USB. This all took about an hour and I was playing music. I also connected my ripped Flac files by USB to the NUC. I don’t really use a "dedicated " streamer, roon’s core/server acts as the streamer. If I wanted I could attach the NUC directly to my DAC and forgo the raspberry pi4.