What does Roon give me beyond just Tidal HiFi?

Roon offers much more than just Tidal.
It offers a forum full of advice from snarky, defensive, rude and often hostile Roon fanboys.
It offers the ability to search your music collection for things you know are there but which Roon can't find.
It offers a development team who are actively opposed to introducing features that its customers frequently and repeatedly say they want.
It offers helpful information about the music you are listening to - such as who the Beatles are, or what Jazz is.
It offers an inability to search for classical music in any useful way.

On the plus side, it does look nice.

Snarky post for sure. 

Rossb - I tried Roon once and experienced exactly what you are talking about. Just wondering if anything has changed

How are you playing your ripped cd collection? Roon would provide very good integration for it. Besides Roon, there are other options to integrate Tidal along with local files, such as Audirvana and Plex.

If you're using the Tidal app, Roon would probably have little benefit for you. I use Tidal and Qobuz on a Raspberry Pi streamer, and Roon has been a game changer for me with a vastly better user interface.

Mainly Room gives me precious time. It's not perfect but it's like my accountant. It worries about things like bit-perfect and device integration so I don't have to. DSP functionality can be useful too.