The thing with Roon is you can run it on anything. The documentation does list minimum spec requirements for various platforms but it’s up to the user to integrate the hardware and software in many cases. Results can easily vary.
The nice thing about products like Innuos and others is they do the integration for you. That’s a good option for some but you probably will pay a premium for it. Applies to Roon as well if one elects to go with the hardware they sell that already has Roon integrated for you.
I do systems integration for a living. Roon core is running great for me on a $300 desktop mini PC, about the size of a pack of cigarettes. I also run Plex and work remotely on it all at the same time. No problems. I use Cambridge Audio streamers, Mac, iPhone, and tablets all as Endpoints or controllers. It’ can get a little complicated sometimes mainly because Roon is so versatile in how it streams, does displays, etc. But it sounds top notch streaming on my main hifi setup or elsewhere. It’s cool to have music playing throughout the house and even outside from time to time.
I’ve been streaming now for about 15 years. Started with Roon earlier this year . Used Squeezebox and Plex mostly for streaming prior. My library is ~1Tb of mostly CD res FLAC files
Different strokes for different folks. Master it somehow though and Roon is music heaven!