Want to add a couple of things.
Roon is a split software system, with the core and end points. The core is a little CPU and storage heavy. This is partly because they index your music and add a lot of metadata to seamlessly blend music you own and music from streaming services. The other part is that the core can do a lot. It can do transcoding from one PCM resolution to another or DSD to PCM, and vice versa, so no matter what the limitations of your DAC, or your preferred data encoding method it will work. The other thing that consumes CPU is the built in EQ via DSP capabilities. Those are pretty amazingly thorough, to the point of users investing an enormous amount of time to do Dirac Live like convolutions.
If you aren't fully utilizing the DSP or transcoding capabilities the CPU needs are quite lite. Unfortunately (I think) this is still keeping Roon from embracing low power, high efficiency ARM based chips and mini servers.
My point is, I think the CPU needs of Roon are a little exaggerated. You get a lot of convenience in integrating your music with streaming services and a great UI on most devices (Web, iPhone, Android) and as a subscription I never worry that it will be outdated like say, a TV that can't play Netflix anymore.