I'm not the OP, but I had wondered the same thing. After already seeing up the other *arr's I couldn't work out the point of Prowlarr.
Re your comment about resource constrained, I have just started using Sonarr and Radarr on a Pi4. They seem to work OK. Had installed but not set up Prowlarr yet. Hopefully that wouldn't slow things down if I used it to sync the other apps.
I still remember 1 Jan 2000. There did seem to be some sense of optimism about where things could go. At least for those of us lucky enough to live in stable, developed countries.
Cold war over, Russia and The West seemingly on the same side, China opening up, exciting new tech connecting us but no toxic social media yet...
But then... the dot com bust, 9/11, the GFC, toxic social media and the rise of "the algorithm", Xi in China, Putin in Russia, a global pandemic......
Didn't really go where we hoped, can we restore to a backup from 1999 and try again??