Your question can be answered in better knowing your streaming requirements. I can share some of the reasons Roon became a part of my streaming diet.
I used Qobuz by itself for 2.5 years before tying it into Roon. Now, I run Roon with Qobuz and Tidal libraries tied in, and I have separate subs to Spotify and YouTube as well. All these services have different use cases for me. I use YouTube for video, Spotify for remote listening, for lo-fi listening while working, and for sharing music, and I use Roon for hi-res listening.
I came to Roon when I upgraded streamers to the iFi Zen Stream. The Zen Stream didn’t have Chromecast built-in (still doesn’t), and I wanted an elegant way to get the music from my Android to the Zen Stream. Roon was the only elegant solution. When I started using Roon, I also found that I could fix the lack of library coverage Qobuz suffered from by also tying in Tidal. No system is perfect. Every streaming service will change how you listen and what you listen to. I do miss the new release curation from Qobuz being front and center. It’s possible for me to find that in Roon, but it’s more buried. Spotify’s content curation and playlists are my favorite out of any service, but Spotify doesn’t support quality source files. My workaround to getting Spotify content curation in high res is via Soundiiz, which is a service that syncs playlists across services. I sync the Spotify playlists to Tidal (which has more music coverage for the playlists that I generally like to listen to), and those synced playlists show up in the Playlists area in Roon. It’s more clunky than I’d like, but it gets the job done.
I’m also looking for ways to consolidate. If Spotify had a CD quality tier, I wouldn’t be using Roon. I didn’t find Amazon Music to be adequate, and I don’t want to use Qobuz or Tidal by themselves at this point. Apple Music may be one service that could replace Spotify and Roon for me, but iFi needs to update their streamer with Chromecast built-in.
One more element to Roon that I’m beginning to experiment with is Roon ARC. It just launched. It gives Roon remote listing abilities. It’s limited to phone apps for now. I hear that it has AirPlay support, but Chromecast and Android Auto support are missing. If Roon ARC becomes more robust, it could replace some of Spotify’s uses for me. I have attempted to share Roon with friends and family via Roon ARC, but it hasn’t taken for anyone yet. I imagine that it’s both not convenient enough, and the Amazon Music and Apple Music users are likely already satisfied with their services.
I do see benefits to hosting my own server. As long as I continue to use Roon, I’ll be playing with things that I couldn’t otherwise play with using the big streaming services. One area is upsampling at the server level (either in Roon or via HQPlayer). I will also experiment more with MQA and DSD formats (and DACs that support those formats). If I get the itch, I might also begin to build my own library of owned music, but that’s a long shot. Also, rooDial looks pretty neeto. So, Roon opens up ways to experiment or customize your music and your listening experience. If any of these things become a feature I have to have, then I’ll be married to Roon for a while longer.