There are some shows like Conan, or The Daily Show that I don’t re-watch. I usually only keep the last week’s worth of episodes on my server. I manually go in and delete the episodes. Since these shows are released with a season being a whole year, you end up with a lot of missing episodes that have a monitored status that you don’t end up wanting. So if I go and tell Sonarr to fetch all missing episodes, it’s going to grab some of these really old episodes that I don’t care about anymore. I still want to get all new episodes of the show, so I can’t un-monitor the season.
I think it would be great if you could have an option to keep only “X” number of recent episodes for a show. The old episodes would get auto-deleted and their monitored status would be turned off.