Prowlarr is the preferred search engine for all the *Arr services. I switched because when you make adjustments to Prowlarr (adding/removing/modifying sources, changing search priorities, etc.), those changes automatically carry over to Sonarr/Radarr/etc.
I have a ton of sources that I micromanage because I have turbo-autism. It was a pain in the ass to tinker with the sources in multiple places with Jackett, and I wound up with lots of gaps and asymmetry. Prowlarr is just cleaner.