Nowadays I'm practically using plexamp far more often than I watch my own video content on Plex. I started using Plex for music about 6 months ago and plexamp has been such a powerhouse of a music app in ways I never expected. I really appreciate the specific DJs they give you with sonic analysis. I've realized it's also made me enjoy buying CDs again, which are especially cheap these days!
TBH I have a love hate relationship with plexamp but yes, it is my main music app. I will try streaming services, try to build out my profile so the algorithms will give me what I like but... nothing beats my own curated library sometimes. Though if they were to integrate Spotify/other music services like they did with Tidal that'd be amazing for when I want to discover more music!