Somebody suggested that Roon sounds like the systems it's implemented with. That sounds about right. If anyone tells you Roon does not sound good, try to find out how they're implementing it. Not just the electronic components, but also the content they're playing, the resolution, and any DSP they've applied.
WIthout having a well-equipped test lab, I suggest you test Roon's SQ by comparing a file streamed through Roon with the same track played directly from a NAS/hard drive through all the same equipment, with equalized volume. If you find that the locally stored file sounds better, then you have to ask yourself if the difference is big enough that you'd want to forego all the advantages of a service like Roon. I've tried some of the alternatives (Audirvana, Apple Music, the Tidal app, the Bluesound app, the Matrix Audio app). IMO none of them measure up to Roon for functionality. Even if you use Roon mainly to discover new music, you can always store favorite, HiRes tracks locally and listen to them in sessions without Roon.