Prowlarr is also important if you do multiple *arr. Sonarr, Radarr, Readarr. instead of configuring your indexers (multiple) in multiple places? You point the searches at Prowlarr and then keep it updated.

I personally run a fairly modified version HTPC on a QNAP (was synology but upgraded earlier this year - better base board + dedicated graphics card)

https://github.com/sebgl/htpc-download-box